• Journal of Environmental Science International
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• v.28 no.8
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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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• v.11 no.3
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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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• v.31 no.6
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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)

• Korean Journal of Veterinary Research
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• v.29 no.1
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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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• v.30 no.8
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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.

• Journal of Korean Home Economics Education Association
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• v.12 no.2
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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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• v.37 no.5
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• pp.370-378
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• 1994

Soybean curd added with 40% of cow’s milk was prepared with eight coagulants such as calcium acetate, calcium lactate, calcium chloride, calcium sulfate, magnesium chloride, glucono-delta lactone (GDL), acetic acid and lactic acid. The curd products were evaluated by the chemical composition, coprecipitation porperties, mineral content, yield, color and textural characteristics. The lowest concentrations for protein coprepitation were 0.3% (v/v) for calcium salts, 0.4% (v/v) for magnesium chloride, 0.2% (v/v) for organic acids. Turbidity and crude protein of whey were markedly decreased at these concentrations. The optimal concentrations of coagualnts used for soybean curd preperation were 1.2% (v/v) for calcium acetate, calcium sulfate and calcium lactate, 1.0% (v/v) for calcium chloride and GDL, 0.8% (v/v) for magnesium chloride and lactic acid, 0.6% (v/v) for acetic acid. It was observed that of the eight coagulants tested, calcium chloride provided a satisfactory curd in quality. Calcium content of soybean curds by the calcium salt coagulants was higher than that by organic acid coagulants. Through the examination on the textural properties by a texturemeter was found out that acetic acid treated soybean curd among the organic acids, calcium salts and magnesium chloride treated curds had very high hardness value. All the curd products prepared in this experiment had a pale yellow color as affected by the value of L (lightness), a (redness) and b (yellowness). Although the colorimetric readings showed that the soybean curds prepared with the organic acids had higher L value but lower a and b value in comparison to calcium salts and magnesium chloride treated curds.

• Food Science and Biotechnology
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• v.17 no.5
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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.

• The Journal of Natural Sciences
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• v.6 no.1
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• pp.49-54
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• 1993

This study was conducted to investigate the influence of various calcium salts on the accumulation of calcium in apple fruits when sprayed on whole tree. Differences in the total calcium contents of fruits were found between calcium sources and cultivars. In 'Tsugaru' , calcium nitrate, calcium chloride, and calcium carbonate were all effective but only calcium chloride and calcium carbonate appeared to be effective in 'Fuji' . Major parts of the applied calcium were accumulated in the feel and outer flesh. Ethylene evolution of fruit was retarded during storage with the increase of total calcium content in 'Fuji' fruit treated calcium acetate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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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.