• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.2
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• pp.218-223
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• 2021

In this study, the possibility of use as a cartridge for 3D printing was confirmed by adding calcium to the alginic acid-added surimi mixture. The Alaska pollack Gadus chalcogrammus surimi added with alginic acid was immersed in a calcium solution (1 M calcium carbonate, 1 M calcium chloride, 1 M calcium sulfate, and 0.1 M calcium lactate) to evaluate the physical properties, color differences, and sensory properties of Alaska pollack surimi according to calcium types. As the results, in the case of surimi paste to which 1 M calcium carbonate was added, physical properties were weaker than that of 1 M calcium chloride, but gelation was appropriate and sensory properties was excellent. Addition of 1 M calcium chloride has the best physical properties, but it has a problem of bitter taste. With the addition of 1 M calcium sulfate, it has low solubility and poor physical properties as well as poor elasticity and bad taste. Addition of 0.1 M calcium lactate has weak physical properties but good sensory properties. From these results, 1 M calcium chloride has the best physical properties, but there is a decisive problem in sensory properties, so 1 M calcium carbonate is most suitable for commercial use.

• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.104-113
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• 1991

This experiment was conducted to find the effect of calcium salts on the inhibition of 'Campbell Early' grape(Vitis labruscana B.) berry absicission induced by ethephon. Ethylene evolution, berry abscission rate, and fruit quality were examined. Several mineral contents were determinded in the berries and morphological changes of cells in abscission zone were also studied. 1. Calcium acetate($4.4-8.8g/{\ell}$) and calcium hydroxide($2.2-8.8g/{\ell}$) completely inhibited berry abscission when applied with ethephon 1,000 ppm while calcium chloride was less effective. 2. Ethylene evolution in the berries treated with ethephon alone reached to maximum peak one day after application. However, that peak in the treatment of ethephon with calcium acetate occurred 3 hours after application. 3. No decrease of ethylene production capacity was observed in the ethephon solution even when held up to 36 hours after preparation but the effect on berry abscission was significantly reduced. In contrast, ethylene production of the solution prepared with calcium acetate was greatly decreased along with the increase of holding time. The effect of calcium acetate in aged solution on the inhibition of berry abscission was not altered. 4. There were no differences in mineral contents such as Ca, Mg, and K between the berries sprayed with ethephon 500 ppm or not. Additional calcium accumulation was not found in the skin, flesh, and petiole of clusters sprayed with 3 kinds of calcium salts (1.5 g net Ca per liter) respectively when analyzed 2 weeks before maturity. 5. Ethephon (1,000 ppm) alone induced the development of abscission layer in petiole but those applied with calcium acetate (0.05 M) did not develop any distinct abscission layer 3days after treatment.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.101-111
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• 2017

Mineral carbonation is a technology in which carbonates are synthesized from minerals including serpentine and olivine, and industrial wastes such as slag and cement, of which all contain calcium or magnesium when reacted with carbon dioxide. This study aims to develop the mineral carbonation technology for commercialization, which can reduce environmental burden and process cost through the reduction of carbon dioxide using steel slag and the slag reuse after calcium extraction. Calcium extraction was conducted using NH4Cl solution for air-cooled slag and convert slag, and ${\geq}98%$ purity calcium carbonate was synthesized by reaction with calcium-extracted solution and carbon dioxide. And we conducted experimentally to minimize the quantity of by-product, the slag residue after calcium extraction, which has occupied large amount of weight ratio (about 80-90%) at the point of mineral carbonation process using slag. The slag residue was used to replace silica sand in the manufacture of cement panel, and physical properties including compressive strength and flexible strength of panel using the slag residue and normal cement panel, respectively, were analyzed. The calcium concentration in extraction solution was analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). Field-emission scanning electron microscope (FE-SEM) was also used to identify the surface morphology of calcium carbonate, and XRD was used to analyze the crystallinity and the quantitative analysis of calcium carbonate. In addition, the cement panel evaluation was carried out according to KS L ISO 679, and the compressive strength and flexural strength of the panels were measured.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.247-251
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• 1999

In spite of various bio-functionalities of chitosan, the effects in vivo were still ambiguous because of its low absorption on organism. Therefore, chitosan oligosaccharides (COSs) are necessary to elucidate for an efficient utilization in vivo. COSs were prepared from chitosan using ultrafiltration membrane enzymatic reactor system with MWCO (molecular weight cut-off) 3,000 Da of membrane. Calcium absorption accelerating effect using COSs was examined by two methods, in vitro and in vivo. In vitro experiment, calcium absorption by the addition of COSs in a mixture solution of calcium and phosphate was higher approximately $50\%$ than that by control. In vivo using rats, group taken the diet contained $1\%$ COSs anil calcium chloride decreased about $75\%$ of calcium content excreted from feces, and then, showed about $15\%$ increase in breaking force of femur. These results demonstrated that COSs definitely involved in calcium metabolism in vivo.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.241-245
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• 2002

To effectively utilize ostrich egg shell as a calcium source, various conditions for preparation of calcium lactate from ashing powder (ashed for 15 min at 90$0^{\circ}C$) were evaluated. Optimal conditions involved treatment of ashing powder with 30 mL lactic acid solution at room temperature for 15 min with a CaO : lactic acid ratio (mol/mol) of 1:2. Calcium lactate contained 39.70% calcium comparable to that (40.98%) in ostrich egg shell. Solubility of calcium lactate, 97.7%, was considerably higher than those (0.58% and 3.43%, respectively) of ostrich egg shell and ashing powder, indicating that the former can be utilized more effectively as a calcium source than the two latter.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.153-158
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• 1998

Calcium hydrogen phosphate was synthesized by reacting calcium chloride and sodium hydrogen phosphate solution in this study. It is well known that the particle size and yield o f calcium hydrogen phosphate produced is greatly affected by the synthetic conditions such as the reactant concentration, reaction temperature, reacting fine, mole ratio and drying temperature, etc. The purpose of this study is to investigate the optimum synthesis condition from the viewpoint of yield and sedimentation volume of the prepared calcium hydrogen phosphate powder according to a randomized complete block design proposed by G.E.P. Box and K.B. Wilson. It was found that the optimum synthetic conditions of calcium hydrogen phosphate were as follows: It was found that optirnum temperature range of reactant solutions was $28-38^{\circ}C$ and $32-42^{\circ}C$ respectively, on the viewpoint of yield and sedimentation volume. The optimum concentration range of reactant solutions was 5.5-10.0% and 6.9-7.4% respectively, on the viewpoint of yield and sedimentation volume. The optimum mole ratio of $CaCl_2$ to $Na_2HPO_4$ was in the range of 1.2-2.0 and the optimum reacting time range was 8.5-11.0 minutes. The optimum drying temperature range was $39-41^{\circ}C$ from the viewpoint of yield, but it was $39-43^{\circ}C$ on the basis of sedimentation volume. Crystallographic analysis to X-ray diffraction patterns of commercially available ecalcium hydrogen phosphate and calcium hydrogen phosphate samples prepared in this study suggested that all samples tested belonged to monoclinic crystal system characteristic of $CaHP0_4{\cdot}2H_20$ crystals.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Journal of Powder Materials
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• v.29 no.6
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• pp.499-504
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• 2022

The objective of this study is to assess the impact of spray drying conditions on medium-chain triglyceride (MCT) loading, solubility, and release of an MCT-loaded solid self-emulsifying system in a water-insoluble oily substance. MCT-loaded solid self-emulsifying systems are prepared by spray drying with SDS and calcium silicate. The effects of inlet temperature (60, 80, or 100℃) and feed solution composition (0, 10, 50, 90, or 100% ethanol) on physicochemical properties of MCT-loaded solid self-emulsifying systems are studied. The inlet temperature significantly affects the water solubility of MCT. Moreover, the feed solution composition significantly affects water solubility, release rate, and MCT loading. The MCT-loaded solid self-emulsifying system obtained at 60℃ using 90% ethanol feed solution shows the best physicochemical properties among the synthesized products and exhibits better water solubility (4.43 ± 0.44 vs. 0 ㎍/mL) and release (94.4 ± 1.6 vs. 32.8 ± 7.4%, 60 min) than a commercial product. Furthermore, the MCT-loaded solid self-emulsifying system shows an excellent emulsion droplet size (approximately 230 nm).

• Journal of Life Science
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• v.14 no.3
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• pp.490-495
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• 2004

Phosphate-solubilizing activities of the two strains (Burkholderia sp. DA23 and Klebsiella sp. DA7l-1) against tri-calcium phosphate and hydroxyapatite were quantitatively determined. Two strains were found to solubilize two types of insoluble phosphate different amounts of amino acid solutions in liquid culture. MPS ability of the strains was increased with concentration of amino acid addition. The optimal solubilization condition of insoluble phosphate in sucrose minimal medium were 0.1% amino acid solution, respectively. The efficiency of amino acid addition was no difference between the two types of insoluble phosphate, tri-calcium phosphate and hydroxyapatite.

• Journal of Fashion Business
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• v.14 no.6
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• pp.39-52
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• 2010

Interests in creating three-dimensionally designed fabric materials are growing rapidly in the sectors of the fashionable textiles with the creativity, new functions, and aesthetics. A number of finishing methods have been developed and proposed to add or create new functions and designs for silk fabrics. Due to the strong hydrogen bonds between the molecules of silk fibroins, the thermal treatment methods used in thermoplastic fiber processing, which can easily deform the synthetic filament fabrics to endow three-dimensional appearance to the fabrics, are not applicable to the silk fabric treatment. In order to modify the fine structure of silk fiber, neutral salt solution treatment methods have been suggested. In this study, the effect of the calcium nitrate solution on the physical and mechanical properties of silk fabrics was investigated by using the KES(Kawabata Evaluation System) equipment. Based on these findings, relationships between parameters, for example, the thickness and the compressional energy, the thickness and the compressional linearity, and the air permeability and the pore area statistical analysis were investigated. The relationships between the process parameters such as treatment temperature/time and the resulting fabric property parameters were also analyzed by using several SAS procedures.