• Journal of Food Hygiene and Safety
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• v.17 no.4
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• pp.183-187
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• 2002

This study was performed to investigate the utility of egg-shell calcium with calcium soak egg-shell in the vinegar. We compared examination eluted quantity with ionization rate in each condition. The results were as follows. 1 The degree of elution and ionization of calcium was proportional to the amount of vinegar and added acetic acid in the vinegar for elution. And ionization rate was the most high in case of 200 ml vinegar volume. 2. fluted quantity were increased in the rank order to 4$0^{\circ}C$ > 3$0^{\circ}C$ > 2$0^{\circ}C$ by temperature but the rank order of ionization of calcium was 3$0^{\circ}C$ > 2$0^{\circ}C$ > 4$0^{\circ}C$ by temperature. The occurrence of unacceptable flavor resulting from the immersion at 4$0^{\circ}C$ was another obstacle to adopt. 3. Eluted quantity and ionization rate of the egg-shell calcium were appeared excellent in case of the brewage vinegar at ventilation condition. The case of brown rice vinegar did not show a considerable difference, but eluted quantity and ionization rate were appeared the most excellent to the other sample. 4. The optimum condition for elution and ionization of the egg-shell calcium was appeared Immersing egg-shells in the brewed rice-bran vinegar at 3$0^{\circ}C$ for three days.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.2
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• pp.16-25
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• 2018

Concrete is a suitable construction material for long-term structure, however, it is needed to understand the calcium leaching damage caused by exposure to underground pure water for a long time. In this paper, it is experimentally investigated that the characteristics of flexural behavior in RC member damaged by calcium leaching degradation. From the test results, when calcium leaching is happened, yielding load and flexural rigidity is reduced, neutral axis depth and displacement is increased. That is, calcium leaching degradation adversely affects RC member performance. And, when the mineral admixture is used in the calcium leaching environment, it is considered that the optimal replacement ratio should be prepared according to the type of mineral admixture.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.59-67
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• 2016

Concrete is a very useful construction material for the sealing disposal of hazardous substances. In general, mass concrete is applied to these structures. And, the mineral admixtures are recommended for the long term performance. Calcium leaching could be happened due to the contact with pure water in underground structures. Thus, it is needed to evaluate the resistance of calcium leaching for concrete mixed with mineral admixtures. From the test results, the mineral admixtures are effective to the improvement of long term compressive strength and chloride diffusion coefficient in concrete members. When calcium leaching is happened, however, the reduction of compressive strength and chloride penetration resistance is severe than OPC case, the micro pore distribution is adversely affected. Consequently, when the mineral admixtures are applied to underground structures which is exposed to calcium leaching environment, it is desirable to reduce water-to-binder ratio, to expose after the sufficient pozolanic reaction, and to use BFS than FA.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.2
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• pp.153-159
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• 2000

The effect of boiling with apple vinegar and citric acid on the dissolution of Ca, Mg, and P out of pork rib bone during stew preparation was investigated. As the concentration (0, 1, 2. 4%) of apple vinegar and citric acid increased, the amount of Ca, Mg, and P dissolved out of the rib bone increased compared with the control. The increase in boiling time(3, 6, 9, 12 hour) also showed the same result. Between the two acid condiments citric acid extracted more Ca, Mg, and P than the apple vinegar at the same concentration. The pH of the pork rib bone stew added with the acid condiments increased gradually during the boiling process. Between the two acid condiments the apple vinegar extracted more amino acids and protein than citric acid at the same concentration.

• Journal of the Korea Concrete Institute
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• v.23 no.5
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• pp.647-656
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• 2011

In radioactive waste repositories constructed in underground, concrete member could be in contact with groundwater for a long time. However, this pure water creates concentration gradients which lead to the diffusion of Ca ions from the pore water and the degradation of underground concrete. Therefore, this study is aimed at investigating the alteration of pore structure and loss of compressive strength associated with dissolution. The results showed that as the leaching period became longer, the pore volume within 50 nm to 500 nm in diameter is greatly increased. Also, the volume of pores larger than 200 nm rapidly increased during initial leaching time and those below 200 nm gradually increased. Furthermore, the compressive strength gradually decreased with increase of degraded thickness. The residual strength of the degraded concrete with OPC was in the range of 33% to 58%.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.5
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• pp.566-573
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• 2005

본 연구는 작은 생선은 뼈째로 먹을 수 있지만 큰 생선은 생선뼈를 거의 이용하지 못하여 생선의 맥에 포함되어 있는 무기질을 유효하게 이용할 목적으로 유기산을 첨가해서 생선뼈 스프를 만들었을 때, 유기산의 종류와 가열시간이 뼈로부터 용출되는 칼슘, 인 함량의 변화에 대하여 조사하였다. 생선뼈에 함유되어 있는 수분과 무기질 함량은 생선뼈의 종류에 따라 달랐고, 큰 생선의 맥일수록 수분 함량은 감소하는 경향이었다. 유기산을 첨가하여 12시간 가열했을 때 스프에 용출된 칼슘은 잿방어뼈에 구연산, 사과산을 첨가하였을 때가 $61.34\%$와 $60.50\%$로 가장 많았고, 인의 용출도 칼슘과 같은 경향이었다. 칼슘과 인의 용출량은 참치뼈에 $4\%$의 사과산을 첨가하여 12시간 가열했을 때에 573mg, 78mg으로 가장 높았다. 참치뼈 스프의 칼슘과 인의 비율은 대조군에서는 칼슘보다 인의 용출$(0.21\~0.35)$이 많았으나, 유기산을 첨가하였을 때는 칼슘의 용출$(0.98\~10.86)$이 많았다. 단백질과 총 유리아미노산의 용출은 대조군보다 유기산을 첨가하였을 때가 증가하였다.

• Analytical Science and Technology
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• v.23 no.4
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• pp.389-394
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• 2010

An ICP-AES method for determination of calcium content and dissolution characteristics of oyster shell (Ostrea gigas) has been developed and validated. Total calcium content in oyster shell was determined using ICPAES. The dissolution characteristics, which would reflect the composition of $CaCO_3$ polymorphs and calcium salts in oyster shell, were also evaluated by dissolution test. The total calcium contents ranged from 31.8 to 39.9% and the dissolution ratios varied from 62.7 to 83.6% (n=15). The determination of calcium content and dissolution characteristics by ICP-AES would provide useful information for the quality control of oyster shell.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.19-22
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• 2017

This study was conducted to investigate the effect of acetic acid and citric acid treatments on amount and content ratio of calcium (Ca) and phosphorus (P) which were extracted from beef shank bones. The amount of Ca in shank bone extracts significantly increased with increasing citric acid and acetic acid concentration, whereas the amount of P increased with only adding citric acid to extraction media. In the case of combined treatment with 0.2 % acetic acid and 0.1 % citric acid, the amounts of Ca and P increased to 30 and 400 %, respectively and Ca and P ratio were drastically improved from 7.53 to 1.85 compared with treatment of 0.2 % acetic acid. The sensory score of shank bone extract prepared with 0.2 % acetic acid and 0.1 % citric acid treatment showed the highest values in taste and overall acceptability among the tested shank bone extracts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.3
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• pp.47-52
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• 1982

The contents of efficient nutrients, especially calcium(Ca), phosphorus (P), $\alpha$-amino nitrogen($\alpha-amino$ N) and total nitrogen (total N) were observed to evaluate the Sagol bone stock as a calcium and protein source: In case of quantitative changes of nutrients in the bone stock as a result of boiling for two, four, eight and twelve hours, respectively, the Ca, $\alpha$-amino N and total N contents increased in the course of boiling, and showed maximum after twelve hours. P contents also increased during eight hours but decreased after twelve hours. By four hours of reboiling, the contents of nutrients in the second stock decreased in contrast with the duration of the preceding process. The Ca and $\alpha-amino$ N contents extracted for 4 hours from the Sagol bones which were boiled for two through eight hours amounted to almost 60$\sim$90% and the total N to 130% amount of their first stocks; Ca and P contents increased when the amount of the water exceeded by weight that of the bones over seven times; and $\alpha$-amino N and total N increased when that of the water exceeded over ten times. These results suggest that Sagol bone stock could be a valuable calcium and protein source by boiling for at least twelve hours with ten times of water (wt/wt).

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.243-249
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• 2005

The chemical and toxicological studies were conducted with acetamiprid 2% granules including different controlling agents for development of controlled-release acetamiprid 2% granule. The fundamental formulation recipe of acetamiprid 2% granule was prepared by the insoluble matrix using polyethylene wax. Starch, cellulose and mineral (calcium carbonate) were used as controlling agents. As a result of studies, release rate of active ingredient from granules into water static condition at $25^{\circ}C$ was increased by addition of starch and cellulose, but was decreased by addition of calcium carbonate. We could select calcium carbonate as controlling agent and make three granules which there were difference in release profiles of active ingredient according to contents of polyethylene wax. 24 hours-release rates of acetamiprid from three granules into water static condition at $25^{\circ}C$ were respectively 75, 50 and 25% when contents of wax were 2, 10 and 20%. The granule which 24 hours-release rate was 25% showed lower acute toxicity against mice and rats.