• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.105-112
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• 1996

Physicochemical properties of Youngia sonchifolia were compared according to harvesting time and brine methods for its Kimchi preparation. Moisture contents in the roots and the leaves of Y. sonchifolia grown for 5 weeks was more than those grown for 11 weeks. 5-week-grown Y. sonchifolia contained more total free sugar than 11-week-grown ones, and among total free sugar the content of fructose was the most, and the contents of glucose and sucrose were rather high. The roots of 11-week-grown Youngia sonchifolia were harder than those of 5-week grown ones. When the roots were soaked in NaCl solution, the hardness decreased with time. Salt concentration of the Kimchi of Y. sonchifolia increased by the brined material of the Kimchi with soaking time.Salt concentration of the Kimchi was higher in the leaves than in the roots.The roots and leaves of Y.sonchifolia grown for 11 weeks contained organic acids such as malic acid, oxalic acid, succinic acid,lactic acid, and citric acid,among which major organic acids were malic acid, oxalic acid, succinic acid, whereas lactic acid and citric acid were minor organic acids.

• Journal of the Korean Applied Science and Technology
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• v.26 no.4
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• pp.434-439
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• 2009

This paper is a new method for prevent. The particulate scale. stero-microscope were used for the scale removal experiment to improve mineralogical characteristics and the reduction of scales in heat pipe. Generally, the scale in the heat pipe consists of calcium carbonate minerals, such as calcite and aragonite which are precipitated by the reaction of Ca and $CO_2$ in the water. Copper alloy metal could eliminate the scale and prevent the production of scale in the heat pipe.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.2
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• pp.78-81
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• 2004

The nacre of imaged abalone pearls was obtained as a calcium carbonate of aragonite type. This result was same the nacre of natural abalone pearl. From the observation of SEM for the nacre adhered on the pearl nucleus, it was known that the layers of calcium carbonate and conchiolin were stratified. The growth rate of nacre was found to be 0.0056∼0.0074 mm/day, which is twice faster than that of traditional method used shells. The pendant and brooch were manufactured using the imaged abalone pearls.

• CELLMED
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• v.9 no.4
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• pp.7.1-7.4
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• 2019

A cuttlefish bone is not a bone, but the internal shell of the Cuttlefish/ sepia officinalis, a small, squid-like cephalopod of phylum molusca, an animals of the order Sepiida. Cuttlefish bone comprises up to 90 percent of its content of calcium carbonate with the abundance of different bioinorganic elements such as magnesium, strontium, iron, even trace amounts of copper, zinc, aragonite and ${\beta}$-chitin which makes it extremely valuable and worthwhile to be used for biomedical research. Unani system of medicine has been using cuttlefish bone under the name of 'kafe dariya' for the treatment various disorders and ailments since centuries. Unani scholars were well aware of the valuable medical and cosmetologically aspect of cuttlefish bone. However, the drug has been forgotten for its beneficial effect and went deep away from the scientific researches. The purpose of the present review is to highlight and revive the data on cuttlefish and cuttlefish bone for its morphology, composition, types, pharmacological actions, temperament, therapeutic dosage, contraindications, correctives, alternatives and therapeutic uses with special reference of Unani medicine to attain its the beneficial features in biomedical sciences.

• Advances in materials Research
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• v.7 no.3
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• pp.185-194
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• 2018

The mechanism of biological materials structure is very complex and has optimal properties compared to engineering materials. Top Neck mollusks shells, as an example of biological materials, have hierarchical structure, which 95 percent of its structure is Aragonite and 5 percent organic materials. This article detected mechanical properties of the Top Neck mollusks shell as a Nano composite using Nano-indentation method in different situations. Research findings indicate that mechanical properties of the Top Neck mollusks shell including elastic modulus and hardness are higher than a fresh one preserved in -50 centigrade and also a Top Neck mollusks shell preserved in environmental conditions. Nano-indentation test results are so close in range, overall, that hardness degree is 3900 to 5200 MPa and elastic modulus is 70 to 85 GPa.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.899-909
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• 2023

In this study, the material scientific characteristics of Hobun pigments used as white inorganic pigment for traditional cultural heritage were identified according to the type of shell and calcination and evaluated the stability of the preservation environment. For the purpose of this, we collected 2 different types of Hobun pigments made by oyster and clam shell and its calcined products(at 1,150℃). Hobun pigments before calcined identified calcium carbonate such as calcite, aragonite but calcination derived changing main composition to portlandite and calcite. Results of FE-SEM showed characteristics microstructure for each shell but pigments after calcined observed porous structure. Porous granule highly caused oil adsorption according to increase specific surface area of pigments. In addition, the whiteness improved after calcined pigments compared to non-calcined pigments, and the color improvement rate of Hobun pigment (CS) which made of clam shell was higher. As a result of the accelerated weathering test, the Hobun pigment-colored specimen had a color difference value of less than 2 after the test, which was difficult to recognize with the naked eye. In particular, the color stability has improved as the color difference value of the Hobun pigment is smaller after calcined compared to before non-calcined pigment. However, it was confirmed that the stability of the painting layer was lower in the specimen after calcined pigment. For antifungal activity test, Aspergillus niger, Tyromyces palustris and Trametes versicolor were used as test fungi, and all pigments were found to have preventive and protective effects against fungi. Especially, the antifungal effect of the calcined pigment was excellent, which is due to the stronger basicity of the pigment.

• The Korean Journal of Quaternary Research
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• v.22 no.1
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• pp.1-12
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• 2008

We investigated metal concentrations and oceanic environment changes that have occurred over the past several years by studying the hard coral Porites lutea, which inhabits tropical and subtropical areas. Soft X-radiographs clearly showed distinctive annual bands within 71 mm coral sample, which reflect changes in the oceanic environment over this period. There were large fluctuations in the major and minor element concentrations. Considering the physicochemical partition coefficient, some elements accumulated in the aragonite matrix in a mechanical manner, while others were affected by environmental factors. The concentrations of some heavy metals varied over a wide range, implying local environmental effects. The variation of Sr/Ca and Mg/Ca in coral skeleton clearly showed large-scale fluctuation over the specific intervals, implying environmental changes during this period. The concentrations of heavy metals also show high fluctuations, and roughly accord with Mg/Ca variation. In addition, Cu and Zn seem to show cyclicity-like peaks, coincide with Mg/Ca variation over the specific intervals. Such variation might be related to local pollution and oceanographic changes. More detailed investigation is necessary, including the pretreatment of coral skeleton sediment.

• Economic and Environmental Geology
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• v.50 no.1
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• pp.27-34
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• 2017

Mineral carbonation for the storage of carbon dioxide is a CCS option that provides an alternative for the more widely advocated method of geological storage in underground formation. Carbonation of magnesium- or calcium-based minerals, especially the carbonation of waste materials and industrial by-products is expanding, even though total amounts of the industrial waste are too small to substantially reduce the $CO_2$ emissions. The mineral carbonation was performed with steelmaking reduction slag as starting material. The steelmaking reduction slag dissolution experiments were conducted in the $H_2SO_4$ and $NH_4NO_3$ solution with concentration range of 0.3 to 1 M at $100^{\circ}C$ and $150^{\circ}C$. The hydrothermal treatment was performed to the starting material via a modified direct aqueous carbonation process at the same leaching temperature. The initial pH of the solution was adjusted to 12 and $CO_2$ partial pressure was 1MPa for the carbonation. The carbonation rate after extracting $Ca^^{2+}$ under $NH_4NO_3$ was higher than that under $H_2SO_4$ and the carbonation rates in 1M $NH_4NO_3$ solution at $150^{\circ}C$ was dramatically enhanced about 93%. In this condition well-faceted rhombohedral calcite, and rod or flower-shaped aragonite were appeared together in products. As the concentration of $H_2SO_4$ increased, the formation of gypsum was predominant and the carbonation rate decreased sharply. Therefore it is considered that the selection of the leaching solution which does not affect the starting material is important in the carbonation reaction.

• Journal of the Korea Concrete Institute
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• v.29 no.1
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• pp.11-21
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• 2017

The paper presents experimental results of self-healing effects of OPC-GGBFS paste with cracked and uncracked specimens. The self-healing of cracked specimens is processes of crack closing with re-hydration of unhydrated in crack surface. The OPC paste with GGBFS replacement ratios of 0%, 10%, 20% and 30% were prepared having a constant water-binder ratios of 0.5. The OPC-GGBFS paste specimens immersed in tap-water and sea-water. The temperature of tap and sea-water was $5^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$. The cracked specimens after deterioration were immersed for 60 days. The relationship between self-healing effect and age-effect was calculate based upon the experimental results. The self-healing effect was measured in ultrasonic pulse velocity (UPV) before and after loading. When the relative change rate of UPV is increases with the increase in GGBFS replacement ratios. Moreover, the self-healing effect is increased with the temperature of tap-water is increase. But the cracked specimens immersed in sea-water was unclear effects of different temperature. Furemore, most of the healing for OPC-GGBFS specimens immersed in tap-water and sea-water occurred during the first 30 days. The self-healing effect until 30 days is higher than that the age-effect. After 30 days, self-effect and age-effect was largely decreases. SEM/EDS analysis of crack on the surface of the specimens in tap-water were covered with aragonite, and sea-water were covered with brucite.

• Conservation Science in Museum
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• v.30
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• pp.89-100
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• 2023

Museum collections are comprised of a variety of materials, and different scientific examinations are being conducted according to the types and production properties of the materials, but insufficient research has been carried out on ultra-small artifacts. To identify the material characteristics of the white ultra-small materials excavated from Geumnyeongchong tomb, this study carried out a wide range of non-destructive analyses (specific gravity, microscopy, nano-computed tomography (Nano-CT), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Raman spectroscopy) and compared the said artifacts with the Goryeo-era burial accessories examined in prior research. Non-destructive analysis confirmed the presence of aragonite, which mainly consists of calcium carbonate (CaCO₃) as the constituent mineral, and identified the material used for the ornaments as the gemstone pearl based on its growth lines. This study concludes that pearls began to be used in the ancient Korean Peninsula in the 6^th century. It is expected that scientific examinations of the white ultra-small artifacts will yield information about the social culture of the time.