• 한국환경과학회지
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• 제28권8호
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• pp.677-687
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• 2019

This study evaluated the biosorption properties of calcium ion using Aerobic Granular Sludge (AGS). A sequencing batch reactor was used to induce the production of Extracellular Polymeric Substances (EPS) through salinity injection, and the calcium ion adsorption efficiency was analyzed by a batch test. The EPS contents showed significant changes (104-136 mg/g MLVSS) at different salinity concentrations. The calcium ion adsorption efficiency was highest for AGS collected at 5.0% salinity, and it was confirmed that the biosorption efficiency of AGS was increased owing to the increase in EPS content. The results of the Freundlich isotherms showed that the ion binding strength (1/n) was 0.3941-0.7242 and the adsorption capacity ($K_f$) was 2.4082-3.3312. The specific surface area and the pore size of the AGS were $586.1m^2/g$ and 0.7547 nm, respectively, which were not significantly different from each other. It was confirmed that the influence of biological properties, such as EPS content, was relatively large among the factors affecting calcium ion adsorption.

• Advances in concrete construction
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• 제11권3호
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• pp.183-192
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• 2021

Due to economic and environmental benefits, increasing the substitution ratio of ordinary cement by industry by-products like fly ash (FA) is one of the best approaches to reduce the impact of the concrete industry on the environment. However, as the substitution rate of FA increases, it will have an adverse impact on the performance of cement-based materials, so the actual substitution rate of FA is limited to around 10-30%. Therefore, in order to increase the early-age strength of high replacement (30-70%) low-calcium ultrafine FA blended cement paste, sodium sulfate and calcium sulfate dihydrate were used to improve the reactivity of FA. The results show that sodium sulfate has a significant enhancement effect on the strength of the composite pastes in the early and late ages, while calcium sulfate dihydrate has only a slight effect in the late ages. The addition of sodium sulfate in the cement-FA blended system can enhance the gain rate of non-evaporation water, and can decrease the Ca(OH)2 content. In addition, when the sulfate chemical activators are added, the ettringite content increases, and the surface of the FA is dissolved and hydrated.

• Journal of Nutrition and Health
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• 제31권6호
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• pp.1031-1038
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• 1998

The present study was carried out to investigate the effects of magnesium supplement levels and periods on calcium, magnesium, and phosphorus metabolism in male Sprague-Dawley rats given low protein and magnesium deficient diets for 2 weeks. Serum calcium content was significantly lower in the magnesium supplement group than in the magnesium-deficient group, but calcium excretion in urine and feces was significantly increased as magnesium level and period was increased. Increasing the dietary magnesium level and periods raised serum content and excretion of magnesium in urine k feces. Urinary excretion of phosphorus in two week group was significantly lower in the magnesium supplement group than in the magnesium-deficient group. fecal phosphorus excretion in supplement group (Mg 800mg/kg diet) was significantly higher than that of other group. (Korean J Nutrition 31(6) : 1031-1038, 1998)

• 대한수의학회지
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• 제29권1호
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• pp.7-11
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• 1989

This study was designed in order to clarify the effect of ethanol drinking on the mineral contents on liver, kidney, muscle and hair. Forty-five rats were divided into 2 groups and a control group. The control group received tap water and the other 2 groups were given 8% and 40% ethanol as drinking source. Liver, kindney, muscle and hair samples were taken and analyzed for zinc, calcium and copper contents by atomic absorption spectrophotometric methods. The results obtained are summrized as follows; 1. The zinc content of muscle showed significant (p<0.01) decrease in both groups. 2. The calcium content of hair showed significant (p<0.1) increase in 8% ethanol group. 3. The copper contents of kidney and muscle in 8% ethanol group and liver in 40% ethanol group showed significant (p<0.1) decrease.

• Journal of Nutrition and Health
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• 제30권8호
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• pp.911-919
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• 1997

The purpose of this research was to investigate the effect of caffeine levels on calcium utilization in rats of different age and sex. Calcium utilization was compared in rats of different age(4 weeks and 10 months) and sex that were fed various levels of caffeine (0, 3.5, and 7mg/100g body weight) for 3 weeks. There was no significant difference in feed intake, serum calcium level, and ash content in tibia among the groups. Fecal calcium excretion was lower in young rats than in adults, Urinary calcium excretion significantly higher in the caffeine groups than that in the no-caffeine group. Daily retention and apparent absorbability of calcium in young rats were higher than those in adult rats. However, there was no significant difference among groups of different sex and caffeine levels. The results of this study suggest that caffeine consumption promotes urinary calcium excretion.

• 한국가정과교육학회지
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• 제12권2호
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• pp.47-64
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• 2000

The purpose of this study was to search the calcium and iron rich foods in Korean people. The food sources presented in the current home economics textbooks of middle and high school were investigated. And 40 kinds of calcium and iron rich foods were selected by the quantity in 100g edible portion. one serving size and according to 1997 food supply data. Also 3 major food groups of calcium and iron supply in Korean were identified, and 10 rich foods for each food groups were selected. The results were summarized as follows. 1. The food sources of calcium 1) The food sources of calcium presented in the home economics textbooks of middle and high school are milk and dairy products. small fishes such as anchovy icefish and dried strip and green vegetables etc. 2) The calcium rich foods by 100g edible portion were in order of skim milk powder river snail sesame sea mustard. whole milk powder. snapping turtle loach sea tangle(dried) opossum shrimp and sea lettuce(dried). And the calcium rich foods by the calcium content in one serving were in order of river snail snapping turtle opossum shrimp loach spiny lobster skate skim milk powder small alaska pollack freshwater crab condensed milk whole milk powder skate ray and milk. 3) The 3 major calcium supply food groups in Korean were vegetables fish and shellfishes and milk and dairy products. 4) The calcium supply foods according to the quantity of food supply in 1997 was in order of sea mustard, milk anchovy chinese cabbage soybean skin milk powder laver shrimp welsh onion and maize. The vegetables were the important sources of calcium in Korean. 2. The food sources of iron 1) The food sources of iron which are commonly presented in the textbooks of middle and high school were meat liver egg(egg yolk) and green vegetables etc 2) The iron rich foods on the basis of the iron content in 100g edible portion were in order of surf clam marsh clam laver(dried)( sea lettuce(dried), crayfish pelilla seed little neck clam orient hard clam, venus clam, and freshwater carab. And the iron rich foods by the iron content in one serving were in order of surf clam marsh clam crayfish little neck clam orient hard clam freshwater crab venus clam hen cockle green confertii(fresh) pen shell and spiny lobster. 3) The 3 major iron supply food groups in Korean were cereals an cereal products fishes and shellfishes and vegetables. 4) The iron supply food according to the quantity of food supply in 1997 was in order of soybean sea mustard maize rice meat edible viscera laver wheat flour, pook, red pepper, egg and bovine meat.

• Applied Biological Chemistry
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• 제37권5호
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• pp.370-378
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• 1994

두유에 우유를 40% 첨가시킨 두부 제조를 위하여 각 응고제별 및 첨가농도별로 두부를 제조하여 gel형성, 순물(whey)의 탁도, 단백질함량, 두부 생산량, 무기질함량, 조직특성과 색도를 비교 조사하였다. Calcium염 응고제는 0.3%(v/v), magnesium chloride는 0.4%, 유기산 응고제는 0.2% 첨가수준에서 대두와 우유 단백질의 공침전이 일어났으며 각 응고제 첨가비율에 비례하여 whey 탁도와 단백질의 유출량이 낮아졌다. 각 응고제 첨가 적정수준은 calcium acetate, calcium sulfate, calcium lactate 가 각각 1.2%(v/v), calcium chloride, gluconodelta-lactone이 각각 1.0%(v/v), magnesium chloride, lactic acid 0.8%(v/v), acetic acid는 0.6%(v/v)였으며 두부 생산량은 calcium chloride를 응고제로 사용했을 때 가장 높았다. 무기질의 함량은 calcium염 응고제가 유기산 응고제보다 Ca은 약 3.3배 많았고 K, Mg, Na, Fe도 약간 높았다. Texturemeter에 의한 우유 첨가 두부의 조직특성 조사결과 가장 단단한 두부는 acetic acid 두부이었고 calcium염 중에서는 calcium sulfate가 단단하였다. 응고제별 두부의 색도 비교에서 명도는 유기산 두부가 약간 높았고 적색도와 황색도는 calcium염 두부가 높았다.

• Food Science and Biotechnology
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• 제17권5호
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• pp.996-1002
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• 2008

Pickled hen egg dipped in brewed apple vinegar for 7 and 14 days was prepared and changes of weight, pH, viscosity, calcium content, antioxidative effect, and sensory characteristics were determined. During a pickling, the egg weight was increased from 62.03 g at day 0 to 91.13 and 94.93 g at day 7 and 14, respectively. The pH of the egg white and yolk, initially at pH 10.24 and 6.56, was decreased, while that of the pickling solution was increased by the pickling days. Viscosity of the pickled egg white was significantly decreased with the pickling days (p<0.05). Significant antioxidative effect was found from the pickled egg mixture (egg white:yolk=1:1). Calcium content of the egg white after 7 and 14 days of the pickling was 280-300 times higher than the fresh egg white and 1.9 times higher than fresh egg yolk. Addition of plain yogurt and honey improved the sensory quality of a pickled egg and was able to mask the unpleasant sour taste. Results suggest that, in addition to the use of pickled egg by itself, egg-based foods such as mayonnaise with enforced calcium content can be developed using a pickled egg.

• 자연과학논문집
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• 제6권1호
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• pp.49-54
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• 1993

사과나무에 대한 칼슘용액의 수관살포 시 칼슘염의 종류에 따른 과실 내 칼슘함량증가효과를 구명하고 자 본 연구를 수행하였다. $CaCl_2$, $CaCO_3$, Ca$(CH_3COO)_2$ 및 Ca$(NO_3)_2$ 등의 칼슘염을 수관살포한 결과 "쓰가루" 품종에는 Ca$(NO_3)_2$, $CaCl_2$ 및 $CaCO_3$, 그리고 "후지" 품종에는 $CaCl_2$와 $CaCO_3$가 과실의 칼슘함량증가에 효과적이었다. 수관살포에 의하여 과실로 흡수된 칼슘은 과피와 과피직하의 과육에 국한되었다. Ca$(CH_3COO)_2$를 살포한 과실은 저장 중에 에틸렌 발생량이 감소하는 경향이었다.

• 한국수산과학회지
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• 제36권3호
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• pp.198-203
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• 2003

Heat-induced surimi gels were prepared using various concentration of ATC as a additives and calcium agent. Regardless of various concentration of ATC, there were no difference the moisture $(80.4-81.2\%)\;and\;crude\;ash\;(1.4-1.\5%)$ contents. The pH of heat-induced surimi gels were decreased 7.16 to 7.04 depend on increasing ATC concentration. The whiteness, breaking force and gel strength of $0.09\%$surimi gel were improved significantly difference (p<0.05). Sensory evaluation on texture and whiteness were also similar to determination by color and texture meters. In mineral content of heat-induced surimi gel calcium content was increased 26 to 54 mg/100g depend on increasing ATC concentration, while phosphorus content was not change. The optimal concentration of ATC for preparation of high quality heat-induced surimi gel was $0.09\%$. The shelf-life of heat-induced surimi gel did not extend by addition of $0.09\%$ ATC.