• Journal of the Korean Ceramic Society
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• v.31 no.10
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• pp.1107-1114
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• 1994

Although various theories have been presented on the mechanism of setting retardation of plaster in addition to organic admixtures. The purpose of this paper is that Hydration studies of plaster of paris in the presence of carboxylic acids under alkalinity are examined in the coordination chemistry. Setting of plaster of paris is retarded by the addition of carboxylic acids except oxalic acid. And setting of plaster of paris contained 5 wt% of Ca(OH)2 is also retarded by the addition of above-mentioned carboxylic acids. The degree of retarding effect under alkalinity is found to be a function of the number of the functional group and the length of carbon chain of carboxyl acids. These reasons are attributed to the soluble complex formation, that is calcium complex formation between calcium ion and carboxylic acids. The author's proposal was confirmed by the results of electrical conductivity measurement. The formation of calcium complex was surpported by IR spectra.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.876-881
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• 2008

The aim of this study was to evaluate the quality characteristics and antioxidant activities of green tea garlic paste added calcium. Garlic was heated with green tea and charcoal at high temperature ($120^{\circ}C$) and high pressure ($1.5\;kgf/cm^2$) for 20 min, and then added several calcium sources (calcium carbonate, calcium citrate, calcium lactate, mixed calcium, calcium powder). Calcium carbonate, mixed calcium or calcium powder significantly increased pH of green tea garlic paste (p<0.05). All kinds of calcium sources significantly increased the viscosity of green tea garlic paste (p<0.05). Solid soluble content of green tea garlic paste was increased only in calcium citrate and calcium powder groups. Lightness, redness and yellowness of green tea garlic paste with calcium were increased, compared with control group (green tea garlic paste without calcium). The antioxidant activities by DPPH and hydroxyl radical scavenging activity of green tea garlic paste added calcium citrate, calcium lactate or calcium carbonate group were much higher than those of the other control groups. The garlic odor and garlic taste by sensory test were significantly weaker in calcium carbonate or calcium citrate group (p<0.05). Based on these results, it was suggested that calcium carbonate or calcium citrate is appropriate material for deodorizing and fortifying agent for green tea garlic paste.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1113-1119
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• 2007

Human bone marrow-derived mesenchymal stem cells (hBMMSCs) must differentiate into osteogenic cells to allow for successful bone regeneration. In this study, we investigated the effects of different combinations of three soluble osteogenic differentiation-inducing factors [L-ascorbic acid (AC), ${\beta}$-glycerophosphate (${\beta}G$), and bone morphogenic protein-2 (BMP-2)] and the presence of a hydroxyapatite (HA) substrate on hBMMSC osteogenic differentiation in vitro. hBMMSCs were cultured in medium containing various combinations of the soluble factors on culture plates with or without HA coating. After 7 days of culture, alkaline phosphatase (ALP) activity, calcium deposition, and osteoprotegerin (OPG) and osteopontin (OPN) expression were measured. The effects of individual and combined factors were evaluated using a factorial analysis method. BMP-2 predominantly affected expression of early markers of osteogenic differentiation (ALP and OPG). HA had the highest positive effect on OPN expression and calcium deposition. The interaction between AC, ${\beta}G$, and HA had the second highest positive effect on ALP activity.

• Korean journal of food and cookery science
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• v.22 no.6 s.96
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• pp.957-965
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• 2006

This research was conducted to examine the usability of Dangui (Angelica gigas Nakai, Root) and Seungumcho (Angelica gigas Nakai, Leaf) as functional food in aspects of their functional components and nitrite scavenging ability. Analysis of proximate composition showed that Dangui contains more moisture, crude lipid and crude protein than Seungumcho. On the other hand, Seungumcho contains more than twice mont of crude ash and crude fiber than Dangui. Dangui showed higher contents in phosphorus, iron, magnesium, and Seungumcho showed higher contents in copper, calcium, sodium, potassium compare to each other. Substances such as calcium, magnesium and iron that showed high contents in Dangui and Seungumcho are the most important inorganic substances. Total dietary fiber(TDF) of Dangui, sum of IDF and SDF, was 24.2%, and Seungumcho showed 28.18%. vitamin C contents of a 29.690.33 mg/100g appeared only in Seunggumcho. Total phenol contents of Dangui was 0.100${\pm}$002% and that of Seungumcho 0.0900${\pm}$008%. Nnitrite Scavenging ability of both water soluble and methanol soluble extracts were more than 90% at pH 1.2, and it decreased as pH level adjusted to pH 4.2, pH and 6.0.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.345-352
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• 1994

High protein beverage of cow-soy milk was prepared by mixing the soymilk and commercial homogenized cow milk in the various ratios. Effect of heat treatment, pH and addition of calcium and sucrose was studied on the water-soluble nitrogen of cow-soy milk The heat-treated soymilk at 10$0^{\circ}C$ were centrifuged at the range of 830~29,900xg for 30 min and 11,200xg was found to be proper for determination of the degree of protein denaturation by centrifugal method. When soymilk was heated at 70~10$0^{\circ}C$ for 30~240 min, soluble nitrogen (QA SN) in supernatant of protein was decreased to 78.0~56.8% due to protein denaturation. Most of heat denaturation of protein was found to be occurred during Initial heating 10$0^{\circ}C$ for all mixed cow-soy milk. The sedimentation of SN was maximum at pH 4.0 In the range of pH 3~8. Addition of sucrose affected little on oASN while calcium addition reduced %SN significantly to approx. 55% for soymilk(100%). The effect of Ca was less as the ratio of cow milk increased.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.80-87
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• 2003

Recovery conditions and characteristics of a high molecular soluble protein from surimi processing wastewater in marine manufacture using calcium powder of cuttle bone treated with acetic acid (ATC) were examined. Judging from results of total-N, pH, COD, turbidity and yields, optimal treatment concentration of ATC for recovery of high molecular soluble proteins from wastewater was $1.0\%.$ The protein recovered from seafood waste (PRW) was macromolecule weight. The COD value in the wastewater treated with ATC was very high. The PRW had a $78.4\%$ in moisture, $1.0\%$ in crude lipid and $5.7\%$ in crude ash. The proximate composition, except the crude ash, of the PRW was similar to that of commercial surimi. The PRW showed white index and similar in the content and in the composition of total amino acid to those of commercial surimi. From the results of sensory evaluation on white index and texture, the heat-induced surimi gel prepared with $5\%$ subsititution of the PRW for bulking agent of commercial surimi was not significantly different compared to that prepared with the original commercial surimi.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.209-216
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• 2010

In order to understand the effects of a single or combined treatments of 1-MCP($1{\mu}L/L$) and $CO_2$(100%) on the firmness of melting type peach fruit(cv. Chunjungdo), fruit were harvested at commercial maturity and examined physiological changes including flesh firmness during 10 days of shelf-life. Firmness loss of fruit was delayed by both single and combined treatments of 1-MCP and $CO_2$. The treatment of 1-MCP was more effective than $CO_2$ treatment but no additive effective on firmness retention was found in the combined treatment. The upsurge of ethylene evolution occurred 5 days of shelf-life in air treated control but ethylene evolution gradually increased in fruit treated by 1-MCP and 1-MCP+$CO_2$. The suppression of ethylene evolution seemed stronger in $CO_2$ treatment. The respiration of fruit significantly inhibited up to 10 days except control where climacteric increase of respiration was found at 10 days of shelf-life. A molecular shift of pectic polymers(an increase of chelator soluble pectins and decrease of water soluble pectins) was induced by both 1-MCP and $CO_2$ treatments. An increase of water soluble pectins was coincident with firmness loss. The delay of firmness loss seemed to be associated with the migration of calcium to wall matrix, especially pectins, resulting in the increase of wall bound calcium. The polygalacturonase activity was significantly reduced by 1-MCP alone 1 day after treatment and increased to similar level of activity 5 days after treatment compared to other treatment except air treated control whereas pectin methylesterase activity seemed not to be affected by both 1-MCP and $CO_2$ treatments. Thus, the molecular shift of pectic polymers appeared not to be related with pectin methylesterase. Further study is required to clarify the softening mechanism associated with molecular shift of pectic polymers and the inter- or intra-cellular movement of calcium ions induced by postharvest treatments of 1-MCP and $CO_2$.

• Korean Journal of Environmental Agriculture
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• v.41 no.3
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• pp.158-166
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• 2022

BACKGROUND: Kiwifruit is a fruit tree with relatively small cultivation area in Korea and researches on its soil and physiology are very limited compared to those on cultivar development. Therefore, there are limited information for farmers to cope with the reduction in productivity due to various physiological disorders and premature aging. This study was conducted to investigate the soil and leaf chemical properties, and fruit characteristics, which will be used as basic data for stable kiwifruit orchard soil management. METHODS AND RESULTS: The soil and leaf chemical properties, and fruit characteristics were investigated for two years in 16 kiwifruit orchards growing 'Hayward' (Actinidia deliciosa) in Jeollanam-do and Gyeongsangnam-do. Soil and leaf samples were collected in July and fruit quality was investigated by harvesting fruits about 170 days after full bloom. The average soil chemical properties of kiwi orchards were generally higher than the recommended level, except for pH, and especially, the exchangeable potassium reached about 300% of the recommended level. The proportions of orchards that exceeded the recommended level of soil chemical properties were 63, 31, 100, 69, 94, 88 and 69% for pH, EC, organic content, available phosphate, and exchangeable potassium, calcium and magnesium, respectively. Thirty-three percent of orchards had more than 100 mg/kg of nitrate nitrogen in soil. Available phosphate in soil showed a significantly positive correlation with leaf nitrogen, phosphoric acid and calcium content, but showed a significantly negative correlation with leaf potassium content. The magnesium content in the leaves was significantly correlated with soil pH. The highest fruit weight was observed in about 25 g/kg of leaf nitrogen content which could be attained when plants were grown on the soil containing about 100 mg/kg of nitrate nitrogen content. The average soluble solids content among 16 orchards was 9.58 °Brix at harvest and 13.9 °Brix after ripening, which increased about 45%, and the average fruit weight was about 110 g. CONCLUSION(S): For fruit quality, fruit soluble solids (sugar compounds) content was significantly correlated with leaf potassium content, fruit hardiness with leaf total nitrate, calcium and magnesium, and fruit titratable acidity with leaf magnesium; however, leaf calcium and magnesium negatively affect the soluble solids contents in fruits.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.159-163
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• 1999

Model experiments were conducted to investigate the effect of different fillers on the removal of toner ink. Combinations of different papers (commercial photocopy paper and filler-free paper), fillers (calcium carbonate, kaolin clay, and talc), and chemicals(1-octadecanol, stearic acid, oleic acid, and TOFA) and stearic acid were found to be effective in detachment and agglomeration of toner ink. Furthermore, pH had little effect on toner detachment and agglomeration, indicating both protonated fatty acids and their anions are equally effective. In the presence of either kaolin clay or talc, all these agglomerating agents are equally effective, although a slightly higher dosage(1% for clay and 2% for talc as compared with control) is required, presumably due to the adsorption of chemical by the filler. Calcium carbonate filler, on the other hand, has a significant and adverse effect on the fatty acids used but has little effect on 1-octadecanol with the exception of possible adsorption. While stearic acid is not effective, a much higher level of oleic acid or TOFA is needed when calcium carbonate fillers are present as compared to the filler-free case. Fatty acids react with calcium carbonate to form calcium salts. The availability of fatty acid anion for toner detachment and agglomeration is determined by the solubility of calcium salt of a given fatty acid. Calcium oleate is 10 times more soluble in water than calcium stearate.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.111-120
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• 2001

Calcium hydroxide pastes is widely used in conventional endodontics. Along with the expanded clinical use of calcium hydroxide, literatures suggest mixing calcium hydroxide with other substance. Among added substances the vehicle plays the most importance role in the overall process because it is directly related with the velocity of ionic dissociation of $Ca^{2+}$ and OH ion. In this study, we evalutated and compared periapical tissue response and root resorption after canal was filled with mixture of saline and calcium hydroxide(Junsei Chemical Co.. Japan) as a aqueous vehicle, Metapaste(Meta Co., Korea) as a viscous vehicle paste, Vitapex(Neo Dental, Japan) as a oily vehicle paste and IRM(Caulk Dentsply, USA) in replantation of rat molar. A total of 31 maxillary first molars of Sprague-Dawley female rats, 30 days old were used. The upper 1st molar was extracted and the mesiobuccal canal was filled with mixture of saline and calcium hydroxide, Metapaste, Vitapex. IRM and then replanted. Rats were sacrificed 3 weeks after replantation. the maxillae were removed. section of 4 micron were cut and stained with hematoxylin-eosin, Apical tissue response were observed under light microscope. The results were as follows: 1. Saline mixing group and Metapaste group were significant different in fibrous capsule width compared to Vitapex group and IRM group(P<0.05). 2. Saline mixing group. Metapaste group. Vitapex group and IRM group did not prevent root resorption and there were no statistical difference. 3. In saline mixing group and Metapaste group. loss of pastes were observed in all samples. From the results of our study. we observed loss of pastes in saline mixing group and Metapaste group because of water soluble property and assumed it was related to inflammation in apical area and sealing ability of material. So, we should study and develop calcium hydroxide vehicle which is easily removed and more stable and because of only 3 weeks observation we need more evaluation in long period.