• 한국세라믹학회지
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• 제53권1호
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• pp.7-12
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• 2016

In this paper, we have developed a simple, new and economical carbonation method to synthesize a pure form of aragonite needles using dolomite raw materials. The obtained aragonite Precipitated Calcium Carbonate (PCC) was characterized by XRD and SEM, for the measurement of morphology, particle size, and aspect ratio (ratio of length to diameter of the particles). The synthesis of aragonite PCC involves two steps. At first, after calcinated dolomite fine powder was dissolved in water for hydration, the hydrated solution was mixed with aqueous solution of magnesium chloride at $80^{\circ}C$, and then $CO_2$ was bubbled into the suspension for 3 h to produce aragonite PCC. Finally, aragonite type precipitated calcium carbonate can be synthesized from natural dolomite via a simple carbonation process, yielding product with average particle size of $30-40{\mu}m$.

• Korean Chemical Engineering Research
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• 제44권3호
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• pp.289-293
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• 2006

탄산칼슘을 제조하는 연속식 결정화 공정에서 결정의 입도분포에 대한 온도와 교반속도 영향을 연구하였다. 연속식조업에서 용액의 산도 변화는 적었다. 교반속도가 300 RPM 이하, 용액의 온도가 낮으면 탄산칼슘 결정의 부피 평균크기는 안정하였고, 전자현미경 사진 관찰에서 calcite와 aragonite가 만들어졌음을 알 수 있었다

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.654-657
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• 2003

We obtained amorphous calcium carbonate through the carbonation reaction of $Ca(OH)_2$, and through this reaction, observed changes in particle shape and phase by electric conductivity, XRD and TEM analysis. According to the result of the analysis, in the first declining stage of electric conductivity, amorphous calcium carbonate that has formed is coated on the surface of $Ca(OH)_2$ and obstructs its dissolution, and in the first recovery stage of electric conductivity, amorphous calcium carbonate is dissolved and re-precipitated and forms chains of fine calcite particles linearly joined. In the second decline of conductivity, viscosity increases due to the growth of chains of calcite particles, and finally the calcite particles are dissolved and separated into colloidal crystalline calcite, thereby increasing electric conductivity again.

• 한국식품조리과학회지
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• 제24권6호
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• pp.876-881
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• 2008

마늘 고유의 독특한 맛과 냄새로 인한 관능적 품질 저하로 식품산업에서 마늘의 활용성 감소를 개선하고, 현대인의 부족한 칼슘섭취를 보완해 줄 영양성과 기능성을 더욱 부각시킨 마늘 식품소재를 개발하기 위하여 녹차, 숯과 마늘을 고온고압 가열처리한 뒤 탄산칼슘, 젖산칼슘, 구연산칼슘, 칼슘믹스, 칼슘파우더를 2% 첨가하여 칼슘첨가 녹차마늘 페이스트를 제조한 후 이화학적, 관능적 특성 및 항산화성을 평가하였다. 탄산칼슘, 칼슘믹스, 칼슘 파우더를 첨가했을 때 pH 증가와 적정산도의 감소폭이 커졌으며, 점도 역시 칼슘을 첨가했을 때 높아졌다. 당도는 칼슘 첨가에 따른 유의적 차이가 없었으며, 색도는 명도, 적색도, 황색도 모두에서 유의적으로 증가 하였다(p<0.05). DPPH radical 소거능 및 Hydroxyl radical 소거능에 대한 항산화 활성에서는 칼슘을 첨가했을 때 증가하여 칼슘이 산화를 방지해주는 것을 알 수 있었다. 또한 7점 척도법으로 마늘맛과 마늘 냄새 특성에 대한 강도검사를 실시한 결과 마늘 냄새에 있어서는 대조구가 5.3점, 탄산칼슘 2.6점, 젖산칼슘 3.2점, 구연산 칼슘 2.2점, 칼슘 믹스 4.3점, 칼슘파우더 4.1점이며, 마늘 맛에 있어서는 대조구가 5.1점, 탄산칼슘 3.0점, 젖산칼슘 3.5점, 구연산 칼슘 3.2점, 칼슘믹스 3.5점, 칼슘 파우더 3.4점으로 나타나 탄산칼슘과 구연산 칼슘을 첨가 했을 때 마늘의 고유의 매운 맛과 향이 적게 느껴지는 것으로 나타났다. 이러한 결과를 바탕으로 칼슘첨가 녹차 마늘 페이스트는 관능적 품질과 기능성을 높인 마늘첨가 가공제품의 개발에 있어서 유용한 식품 소재로서의 가능성을 가지고 있다고 사료된다.

• Journal of Periodontal and Implant Science
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• 제38권1호
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• pp.83-90
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• 2008

Purpose: This study investigated the osteoconductivity of natural calcium carbonate-derived bone substitutes, hen eggshell (ES), and compared with those of commercial bone substitutes. Materials and Methods: Osseous defects created in the rat calvaria were filled with particulated ES(ES-1), ES with calcium-deficient hydroxyapatite surface layer (ES-2), Biocoral(Inoteb, France), and Bio-Oss(Geistlich Pharma, Wolhusen, Switzerland). After 4 and 8 weeks of healing, histomorphometic analysis was performed to evaluate the amount of newly formed mineralized bone area (NB%). Results: Histologic and histomorphometric analysis showed new bone formation and direct bony contact with the grafted materials in all groups. At 4 weeks, Biocoral group showed greater NB% compared to Bio-Oss and ES-1 groups (P<0.05). At 8 weeks, Biocoral and ES-2 groups showed significantly greater NB% compared to Bio-Oss group (P<0.05). Conclusion: These results indicate that natural calcium carbonate-derived bone substitutes with microporous calcium-deficient hydroxyapatite surface layer may be an effective materials treating osseous defects.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.540-548
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• 2016

Microbially induced calcium carbonate precipitation (CCP) is a long-standing but re-emerging environmental engineering process for production of self-healing concrete, bioremediation, and long-term storage of CO₂. CCP-capable bacteria, two Bacillus strains (JH3 and JH7) and one Sporosarcina strain (HYO08), were isolated from two samples of concrete and characterized phylogenetically. Calcium carbonate crystals precipitated by the three strains were morphologically distinct according to field emission scanning electron microscopy. Energy dispersive X-ray spectrometry mapping confirmed biomineralization via extracellular calcium carbonate production. The three strains differed in their physiological characteristics: growth at alkali pH and high NaCl concentrations, and urease activity. Sporosarcina sp. HYO08 and Bacillus sp. JH7 were more alkali- and halotolerant, respectively. Analysis of the community from the same concrete samples using barcoded pyrosequencing revealed that the relative abundance of Bacillus and Sporosarcina species was low, which indicated low culturability of other dominant bacteria. This study suggests that calcium carbonate crystals with different properties can be produced by various CCP-capable strains, and other novel isolates await discovery.

• 접착 및 계면
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• 제9권2호
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• pp.24-31
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• 2008

본 연구에서는 EVA 에멀젼에 내수성 및 기계적 특성을 향상시키기 위하여 금속 이온 가교제인 calcium hydroxide 및 magnesium carbonate를 사용하여 이온성 가교결합을 도입하였다. EVA 에멀젼 필름의 가교밀도, 열적특성, 표면자유에너지 그리고 인장강도, 파단신율 및 인열강도 특성을 고찰하였다. 금속 이온 가교제 양이 증가함에 따라 EVA 에멀젼의 가교밀도는 증가하였고, 이에 내수성과 $T_g$ 값도 증가하였다. 그러나 EVA 에멀젼 필름의 표면에너지 및 기계적 특성들은 다소 다른 거동을 보였다. Calcium hydroxide 0.4% 그리고 magnesium carbonate 0.5%를 첨가한 경우가 EVA 에멀젼에 강한 이온성 가교결합이 형성되어 가장 높은 표면 자유에너지 값과 인장강도 및 인열강도를 보였다. 그러므로 본 연구에서 calcium hydroxide 및 magnesium carbonate와 같은 금속 이온 가교제가 EVA 에멀젼의 내수성과 기계적 물성을 향상시킴을 확인하였다.

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.229-242
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• 2000

The purpose of this study was to evaluate the effect of fibrin tissue adhesive and porous resorbable calcium carbonate on the periodontal regeneration of the class II furcation defect in dogs. Class II furcation defect was surgically created on the second, third, and fourth premolars bilaterally in the mandibles of six mongrel dogs. The experimental sites were divided into four groups according to the treatment modalities: Control-surgical debridement only; Group I-calcium carbonate grafting; Group II-application of fibrin adhesive only; Group III-application of fibrin adhesive after calcium carbonate grafting. The animals were sacrificed at the 2, 4, and 12 weeks after periodontal surgery and the decalcified specimens were prepared for histological and histometrical examination. The results are as follows : Clinically, there were no inflammatory response in all groups after 2, 4, 12 weeks. In the Control group, junctional epithelium was grown downward to the reference notch. In Group I, graft materials were exfoliated from the defect throughout the experimenta periods andnew bone was seen in the notch area at 4 and 12 week specimens. In Group II, fibrin adhesive was absorbed at 2 week specimens, and connective tissue attachment increased than that of control group. New cementum and new bone were seen above the notch area. In Group III, the graft material was maintained in the defect throughout the experimental period and inducing the amount of periodontal tissue regeneration was higher than other groups. These results suggest that the use of fibrin tissue adhesive in conjunction with porous resorbable calcium carbonate would improves the stability of graft material and inhibit the epithelial down growth and make it be a feasible method for periodontal regeneration.

• 한국대기환경학회지
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• 제19권4호
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• pp.415-425
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• 2003

A single particle analysis, called low-Z electron probe X-ray microanalysis was applied to characterize the atmospheric aerosols collected during Asian Dust storm events in the year of 2000 and 2001. Most frequently encountered chemical species were the soil-originated species such as aluminosilicates, silicon dioxide, and calcium carbonate. Also various species such as carbon -rich, organics, sea salts, and some reacted calcium carbonate were identified. The observation of internally mixed particles oi calcium carbonate, calcium nitrate and/or calcium sulfate shows the occurrence of the heterogeneous reaction between Asian Dust particles and NO$_{x}$ and/or SO$_{x}$ species in the atmosphere.ere.

• 대한화학회지
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• 제8권3호
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• pp.109-112
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• 1964

A volumetric method of the determination of calcium carbonate and calcium fluoride in fluorspar concentrate is described. The carbonate is converted into solution by treatment of the sample in HNO$_3$-acetone (l% by volume) mixture, and the fluoride by treating the residue with H$_3BO_3$-HCl mixture. The calcium in the solution is determined volumetrically using EDTA standard solution. The selective dissolution of calcium carbonate by HNO$_3$-acetone mixture is superior to Bidtel's acetic method and little correction for the dissolution of calcium fluoride is needed. Triethanolamine is found to be superior to KCN in masking heavy metal ions.