• 한국치위생학회지
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• 제8권3호
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• pp.13-22
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• 2008

Objectives: The purpose of this study was to identify the correlation between calcium in soft drinks and enamel remineralization. Method: Six soft drinks were used in this study. These were calcium milk, normal milk, calcium yoghurt, normal yoghurt, calcium orange juice, and orange juice. Enamel specimens which 300- 400Vickers Hardness Number (VHN) were selected. These samples were immersed in each soft drink for 12 hours in an in vitro remineralization model. All specimens were processed for SEM image of the enamel surface. Results were analyzed by SPSS 13.0 package program. Results: Calcium milk was the most influential and normal yoghurt was the least to enamel surface. There was not significant difference according to calcium supplement in milk although the difference of enamel hardness was ${\Delta}f13.4$ in calcium milk, and ${\Delta}f4.7$ in normal milk (P>0.05). Other soft drinks showed a little change about calcium but they were insignificant. Demineralization effect was remarkably observed in calcium yoghurt ($-{\Delta}f269.1$) and this effect was confirmed by SEM images. In conclusion, calcium supplemented soft drinks had little influences to hardness of enamel surface.

• 농업과학연구
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• 제46권4호
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• pp.737-754
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• 2019

Peaches have soft tissues compared to other fruits and are vulnerable to softness, wounds, and loss of marketability due to the weak fruit hardness after harvest. It is necessary to develop a technology to improve the shelf-life of the fruit to expand the distribution of peaches. Calcium compounds and chitosan have an important role in improving the shelf-life of fruit by maintaining the hardness and reducing the respiration rate in peach fruits. In this study, to select useful compounds to improve the shelf-life of peaches, calcium citrate, calcium chloride, calcium nitrate, GH-Ca, OS-Ca, chitosan, and chitosan dissolved in calcium chloride were sprayed onto peach trees. The characteristics of the harvested fruits were investigated after the 'Kumhong' and 'Madoka' peach tree treatments. The hardness of the fruit was kept the highest with the combined treatment and remained high with the calcium citrate, chitosan and calcium nitrate treatments. Ethylene production and respiration were effectively inhibited by the GH-Ca and chitosan treatments. There was no significant difference in soluble solids content and acidity among the fruits treated with the chemicals. The coloration of the fruit skin was not delayed by the calcium and chitosan chemical treatments. Calcium compounds were increased in the fruits and leaves of the peach trees treated with the chemicals compared to the untreated ones. These results suggest that the calcium treatment extended the shelf-life by increasing the calcium content in the leaves and fruits of the peach trees.

• 대한소아치과학회지
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• 제32권3호
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• pp.454-460
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• 2005

산성 음료의 치아침식증 유발력을 감소시키기 위한 연구의 일환으로, 0.1%, 0.3%, 0.5%, 1.0% 구연산용액의 5분, 15분, 30분, 60분간의 사람 소구치 법랑질의 치아침식증 유발력 및 구연산용액에 첨가되는 칼슘 0.05%, 0.1%, 0.2%에 따른 치아침식증 발생 억제효과를 표면미세경도를 측정하여 연구하였다. 전체적으로 볼 때, 구연산 농도가 높을수록, 탈회시간이 길수록, 칼슘농도가 낮을수록 탈회후 경도가 하락하였다. 탈회 5분 후 경도는 칼슘 무첨가의 경우에 76~90%이었고 칼슘 첨가에 따른 5분간의 탈회억제량은 2~15%이었다. 탈회 15분 후 경도는 칼슘 무첨가의 경우에 65~84%이었고 칼슘 첨가에 따른 15분간의 탈회억제량은 3~17%이었다. 탈회 30분 후 경도는 칼슘 무첨가의 경우에 53~72%이었고 칼슘 첨가에 따른 30분간의 탈회억제량은 6~22%이었다. 탈회 60분 후 경도는 칼슘 무첨가의 경우에 43~66%이었고 칼슘 첨가에 따른 60분간의 탈회억제량은 7~19%이었다. 탈회억제량의 분포를 전체적으로 보면, 구연산 농도에서는 1.0%에서 가장 크게 나타났고, 칼슘농도에서는 0.2%에서 가장 크게 나타났으며, 탈회시간에서는 0.1% 구연산용액에서는 탈회시간이 증가함과 더불어 탈회억제량도 함께 커지는 경향을 보였으나, 0.3% 이상의 구연산용액에서는 30분에 가장 크고 60분에 약간 감소하는 경향을 보였다. 이상의 결과는 구연산에 의한 치아침식증 발생에 칼슘이 억제효과를 나타낼 수 있음을 시사한다.

• 동아시아식생활학회지
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• 제5권3호
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• pp.287-298
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• 1995

This study was undertaken to examine the effect of salting in 10% salt solution added 2% calcium chloride on the kimchi fermentation. The addition of calcium chloride extended edible periods of the Kimchi to 4~5 days and increased relatively the hardness of Chinese Cabbage. In the addition of calcium chloride, the activities of amylase and $\beta$ -galactosidase were not high during all periods fermentation. Polygalacturonase and protease activities were low 2~21%, 2~26% all periods fermentation, respectively. There were significant correlations between the delay of ripeness and decreasing enzyme activation. The amount of free amino acid by the treatment with calcium chloride was decreased of 10~16% at the late of fermentation than that of control. the treatment with calcium chloride of the Kimchi was increased hardness, but decreased cohesiveness and gumminess was during all periods fermentation. the adhesiveness was increased at the early of fermentation but decreased at the late of fermentation.

• 펄프종이기술
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• 제31권2호
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• pp.15-24
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• 1999

A new technique for recycling of white water was developed in order to reduce the calcium hardness in a closed OCC recycling system. Calcium ions present in the white water were precipitated as calcium carbonate by reacting with sodium carbonate, and the precipitated $CaCO_3$ was removed from the system using a flotation fractionation method, which has been commonly used in deinking process. In the flotation stage, a mixed gas of $CO_2$-air was purged into the flotation cell because the pH of $Na_2CO_3$-treated white water was reduced to neutral by $CO_2$ gas. Since $CaCO_3$ precipitate tends to stick onto fine fiber surface and then selectively removed from the white water, a proper amount of suspended solid in white water acts as an important factor for deciding the removal efficiency. By the application of $Na_2CO_3$ addition-$CO_2$ flotation to the short circulated white water, the calcium hardness was significantly reduced by 87% and more. Removal of calcium ions with fine fibers led to a drainage improvement, reduction of fresh water consumption, and enhanced efficiency of wet-end chemicals.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
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• pp.164-171
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• 1999

A new technique for recycling process water was developed in order to reduce the calcium hardness of the closed OCC recycling system. Calcium ions present in the white water were precipitated as calcium carbonate by a reaction with sodium carbonate and the CaCO$_3$precipitates were easily removed from the system by a dissolved air flotation(DAF) method. After the DAF stage, CO$_2$-gas was purged into the water because the pH of Na$_2$CO$_3$-treated white water was reduced to neutral by CO$_2$gas. Since CaCO$_3$precipitate tends to stick onto the fine fiber surface and then is selectively removed from the water, a proper amount of suspended solid in the process water acts as an important factor in deciding the removal efficiency. By the application of Na$_2$CO$_3$addition - DAF - CO$_2$purging to the short circulated white water the calcium hardness was significantly reduced by 92% and more. The removal of calcium ions with fine fibers led to drainage improvement, reduction of fresh water consumption, and enhanced efficiency of wet-end chemicals.

• 한국의류학회지
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• 제6권1호
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• pp.9-15
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• 1982

The influence of builders on calcium deposition on the fabric was studied by laundering the cotton fabric with sodium carbonate, sodium metasilicate, sodium tripolyphosphate and built detergents in hard water. The laundry variables were: 1) Washing cycles: 5, 10, 20, 30 and 40 cycles. 2) Water hardness: 100 ppm, 150 ppm, 200 ppm and 300 ppm. 3) Builders: $Na_2\;CO_3,\;Na_2\;SiO_3$ and STPP. 4) Detergents: Na-DBS, $Na-DBS+Na_2CO_3,\;Na-DBS+Na_2\;SiO_3,\;Na-DBS+STPP,\;Na-DBS+Na_2\;CO_3+STPP$, and $Na-DBS+Na_2\;SiO_3+STPP$. The fabric was washed for 15 minutes at 23+$1^{\circ}C$ in a washing machine(Gold Star WP 3007) under the similar condition with those of home laundering, and rinsed 3 times in the same water hardness for 5 minutes. The calcium deposits on the fabric was determined by EDTA-BACK titration methods. The results of this study were as follows: 1) The amount of calcium deposits on the fabric was increased with increasing wash cycles. This deposit was due to the build up of insoluble calcium carbonate. 2) As the water hardness increased, the amount of calcium deposits on the fabric was increased. 3) Alkaline builders, such as, $Na_2CO_3$ and $Na_2SiO_3$, promoted calcium deposition on the fabric, however STPP prevented calcium deposition on the fabric. 4) Fabric laundered with $Na-DBS+Na_2CO_3$ showed the highest calcium deposits on the fabric, and decreased with the order of $Na_2CO_3$, $Na-DBS+Na_2SiO_3$, and Na-DBS. And fabrics washed with phosphate-built detergents showed a small amount of calcium deposition.

• 펄프종이기술
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• 제41권2호
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• pp.26-33
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• 2009

A new testing method to evaluate the deposition potential of white pitch was developed. The new method involves depositing the potential white pitch particles on the air bubble covered plastic film in the pitch deposit tester (PDT) developed by KRICT and analysing the deposited area of white pitch using an image analyzer. In addition, the effect of two important factors (pH and calcium hardness) on white pitch deposition potential was elucidated. When pH of the coated broke stock was increased from neutral to alkali or the calcium hardness of the stock was decreased, the pitch deposit area was decreased, implying that these two factors have to be controlled during the evaluation of pitch deposition potential. It was found that hydrophobicity of the surface of latex binding films repulped is a key factor influencing white pitch deposition.

• 한국식품저장유통학회지
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• 제20권1호
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• pp.76-80
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• 2013

본 연구는 인삼을 칼슘 및 식초에 침지함으로서 인삼 pectins의 칼슘결합(calcium bonding)에 의한 물성변화를 조사하였다. 인삼뿌리의 강도(strength)와 부서짐성(breakdown)은 탄산칼슘 농도의 증가에 따라 증가하였으나 탄산칼슘 0.7~1.0%에서 가장 높게 나타났고, 인삼뿌리의 경도(hardness)는 탄산칼슘 농도 1.0%에서 가장 높았고, 연화정도(softness)는 탄산칼슘 농도 1.0%에서 가장 낮았다. 1% 탄산칼슘을 용해한 식초에 침지한 인삼뿌리의 물성 중 강도, 부서짐성 및 경도는 산도 5%, 6% 칼슘용액에 침지한 인삼뿌리가 60일 이후부터 계속 증가하여 90일경에 높게 나타났다. 연화 정도는 1% 탄산칼슘과 산도 5% 식초에 침지한 인삼뿌리만이 줄어들어 인삼뿌리음료의 장기저장 중 음료가 혼탁해지는 것을 방지할 수 있었다.

• 한국식품저장유통학회지
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• 제18권5호
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• pp.678-683
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• 2011

떫은감 분말 첨가 두부의 수율, 품질 및 저장성에 응고제의 종류(magnesium chloride, calcium chloride, calcium sulfate, glucono-${\delta}$-lactone)가 미치는 영향을 조사하였다. Glucono-${\delta}$-lactone으로 응고시킨 두부가 가장 높은 수율, hardness, chewness, crispness, overall acceptability 및 가장 낮은 L값, b값, pH, 침지저장액 탁도, 총균수를 보였다. Calcium sulfate와 calcium chloride으로 응고시킨 두부는 비교적 높은 L과 b값을 나타내었다. Magnesium chloride로 응고시킨 두부는 관능적 품질특성(firmness, taste, overall acceptability)이 glucono-${\delta}$-lactone 응고 두부와 상호 유의적인 차이가 없이 비교적 높게 평가되었다. 이러한 결과로써 glucono-${\delta}$-lactone과 magnesium chloride가 떫은감 분말 첨가 두부 제조에 적합한 응고제로 판단된다.