• Journal of the Korean Ceramic Society
• /
• v.41 no.11
• /
• pp.804-811
• /
• 2004

We have studied microwave extraction process of boric acid from one of calcium borate ores, colemanite. Calcium and boron have separated by addition of sulfuric acid, and calcium has been separated out as calcium sulfate. It was possible to extract boron with the smaller amount of sulfuric acid and with short heating time in microwave heating compared to conventional heating process. The products of boric acid was the same purity and thermal characteristic, but smaller in particle size.

• Journal of the Korean Ceramic Society
• /
• v.38 no.11
• /
• pp.1030-1036
• /
• 2001

Hydroxyapatite[COL] nanocomposite was prepared through coprecipitation process. The chemical bond formation between HAP and COL was confirmed by diffusive reflectance FT-IR and TEM observation. Higher concentration of COL in the preparation induced tiny nanocrystalline composite particles, but lower concentration of COL contributed to form the well developed HAP particles. From TEM observation and ED(Electron Diffraction) pattern the embedded HAP nanoparticles were oriented along the c-axis of COL fiber. In an aqueous system of constant [Ca$\^$2+/] and [PO$_4$$\^$3-/], quantity of soluble COL matrix was doing an important role of controlling the heterogeneous nucleation site for the formation of HAP nanocrystals. Higher concentration of COL will provide more nucleation sites for Ca$\^$2+/ and so the concentration of calcium ions for the total number of active nucleation sites will be getting relatively dilute.

• Applied Chemistry for Engineering
• /
• v.29 no.6
• /
• pp.740-745
• /
• 2018

The synthesis and characterization of amorphous calcium phosphate (ACP) nanoparticles were reported in this work. We show that relatively monodisperse ACP nanoparticles with a size of sub-100 nm can be prepared by a hydrothermal reaction of calcium chloride ($CaCl_2$) and disodium adenosine triphosphate ($Na_2ATP$) in the presence of sodium phytate as an additive. Their compositions and structures were confirmed using a series of material characterization techniques. Our results exhibit that ACP nanoparticles synthesized using sodium phytate enhanced the stability of maintaining their amorphous nature and prevented from a conversion to crystalline hydroxyapatite (HAP). ACP nanoparticles with the improved stability have potential uses in biomaterial applications in regenerative medicine.

• The Korean Journal of Pharmacology
• /
• v.28 no.1
• /
• pp.91-102
• /
• 1992

In $Ca^{++}$ containing media, arachidonic acid markedly stimulated superoxide and $H_2O_2$ generation and activated NADPH oxidase. In $Ca^{++}$ free media, stimulatory action of arachidonic acid on NADPH oxidase was not detected. Arachidonic acid-stimulated respiratory burst was inhibited by EGTA, TMB-8, verapamil, diltiazem, nifedipine, dibucaine, lidocaine, CCCP, 2,4-dinitrophenol, sodium arsenate, chlorpromazine, theophylline, $HgCl_2$, PCMB and PCMBSA but not affected by tetrodotoxin, tetraethylammonium chloride and procaine. EGTA almost completely inhibited release of ${\beta}-glucuronidase$ by arachidonic acid and verapamil, CCCP and theophylline slightly inhibited it, whereas dibucaine did not show any significant effect. Arachidonic acid induced $Ca^{++}$ release from intact neutrophils and it was decreased by TMB-8. Arachidonic acid-induced elevation of intracellular free $Ca^{++}$ level was inhibited by EGTA and CCCP and slightly inhibited by TMB-8. Amount of intracellular free $Ca^{++}$ increased by either arachidonic acid plus verapamil or arachidonic acid plus dibucaine was greater than that by arachidonic acid alone. These results suggest that various changes of biochemical events may be implicated in the functional expression in neutrophils activated by arachidonic acid. Arachidonic acid appears to elevate cytosolic free $Ca^{++}$ level by stimulating $Ca^{++}$ release from intracellular $Ca^{++}$ storage sites. During activation of neutrophils, $Ca^{++}$ influx and efflux may be accomplished, simultaneously.

• Journal of Aquaculture
• /
• v.10 no.4
• /
• pp.417-424
• /
• 1997

This study was carried out to investigate the effects of experimental formulated diets, commercial diets and natural diet(dried Undaria) on growth and body composition of Haliotis discus hannai. Experimental diets was formulated to provide 34.1% protein and 7.5% lipid, and prepared by different $CaCl_2$ concentration (5, 10 and 15%) and dipping time (10, 20 and 60 second) in solution. The juvenile abalone average weighing 0.3g were distributed in a flow-through aquarium system using a cmpletely randomized desing with 13 diets and 3 replictes per diet (50 abalone/tank), and fed diets for 17 weeks. The abalone fed the time nine experimental formulated diets and two commercial diets showed better growth performance than that of natural diets. No significant differences were found among abalone fed the experimental diets and commercial diets in survival rate, weight gain, soft body weight and soft body composition (P>0.05).

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.18 no.4
• /
• pp.174-178
• /
• 2008

Nano-crystalline slaked lime was synthesized using design of experiment. In order to synthesize slaked lime, calcium chloride $(CaCl_2)$ and urea were used as starting materials. Calcium chloride solution and urea solution were mixed and heated in vessel that calcium carbonate was precipitated during heating. Precipitates were filtered, washed several times using D.I.water and ethanol and finally dried in oven. Slaked lime $(Ca(OH)_2)$ has been fabricated by the hydration of calcined $CaCO_3$. Design of experiment (Taguchi method) was used to optimize parameter, to minimize noise factors of experiment and to statistically analyze the results. Slaked lime having about 50 nm in optimized crystallite size could be obtained by calcination of $CaCO_3$ at $1000^{\circ}C$ for 0.5 h and hydration with D.I water containing ethanol and oxalic acid.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.5
• /
• pp.829-834
• /
• 2015

To decrease excessive sugar intake, and increase vegetable and calcium intake, we manufactured sugar free fruit-vegetable jam containing calcium and fructo-oligosaccharide to substitute for sucrose. We evaluated jam for physico-chemical and sensory properties. When the amount of apple was replaced with the amount of kale, $^{\circ}brix$ decreased, whereas there were no significant changes in pH. As the amount of kale increased, lightness and yellowness increased. However redness did not show trend to increase or decrease. In the texture profile analysis, hardness, springiness, cohesiveness, gumminess and chewiness significantly decreased with increased amount of kale, but adhesiveness gradually increased. The sensory parameters including taste, flavor, color, spreadability and overall acceptance of jam added 10.0~12.0% amount of kale were the highest acceptance. As the amount of kale added in the jam, sensory properties decreased. In general, when sugar free fruit-vegetable jam was manufactured, apple and kale ratio of 3:1 or 4:1 was considered appropriate.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.5
• /
• pp.651-656
• /
• 2007

Fish-frames which are left after obtaining fillets or muscle during fish processing, consist of useful food components such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using flatfish frame and also to elucidate food component characterization of the snack. The results of heavy metal and volatile basic nitrogen (VBN) content suggested that flatfish frame was a suitable material for preparing snack. The optimal addition ratio of flatfish frame to mix was 3% for preparing snack according to the results of VBN content, water activity and sensory evaluation. The major fatty acids of the snack with 3% flatfish frame (SFF) were 16:0 and 18:0 as saturates, 18:1n-9+7 as monoenes, and 18:2n-6 and 18:3n-3 as polyenes, while EPA and DHA were contained in small amount SFF. Total amino acid content (9,281.9 mg/100 g) of the SFF was higher than that of the snack without flatfish frame (7,791.3 mg/100 g) and the major amino acids were aspartic acid, glutamic acid, proline and leucine. The calcium and phosphorus contents of SFF were 492.3 mg/100 g and 270.3 mg/100 g, respectively. The Ca/P of SFA was 1.82 which is a good ratio for the absorption of calcium. The SFF was superior in total amino acid, calcium and phosphorus contents compared to the snack without flatfish frame.

• Korean Journal of Food Science and Technology
• /
• v.45 no.5
• /
• pp.605-612
• /
• 2013

We investigated changes in the nutrient compositions of seokbakji supplemented with seafood during storage at $5^{\circ}C$ for 14 days. We added the seafood at a concentration of 10% (w/w) to salted radish and prepared seokbakji samples. Our results showed that the levels of moisture, crude lipids, crude ash, carbohydrates, and crude fibers did not differ markedly among the samples. However, the level of crude protein in seokbakji with added seafood was greater than that in control seokbakji. The highest level of Ca and P was determined in seokbakji supplemented with gizzard shad; the highest level of vitamin $B_2$ was determined in seokbakji supplemented with sandfish, and the highest vitamin C content was determined in seokbakji supplemented with small octopus. Glutamic acid showed the highest content in seokbakji with seafood; further, hydroxyproline was the most abundant free amino acid. The results of sensory evaluation showed higher scores in the overall acceptability of seokbakji with seafood than in control seokbakji.

• Journal of the East Asian Society of Dietary Life
• /
• v.13 no.6
• /
• pp.608-614
• /
• 2003

This study was conducted to investigate the quality characteristic of bread added with 0, 2, 4 and 8% liquid calcium acetate(LCA-breads) to the dough prepared with brown rice, vinegar and ash of black snail replacing wheat flour. The pH of the dough was 5.38 in control and 5.39∼5.42 in the LCA-broads, which showed that the higher the content of LCA, the higher the pH. There was no big difference of the baking loss between control (10.73%) and LCA-breads(10.11∼10.81%). The loaf volume index was 7.12 in the control, 7.18 in the 2% LCA-bread, while the index was 6.22 in the 4% LCA-bread, 5.80 in the 8% LCA-bread. Calcium content was 16 mg% in the control, 30, 60 and 120 mg% in 2, 4 and 8% LCA-bread, respectively. The hardness, gumminess and brittleness of LCA-breads were higher, while springiness and cohesiveness were lower than that of the control. In the LCA-breads, $L^{*}$ values were lower and $b^{*}$ value was higher than those of the control, while there were no significant difference in af values. Increasing the LCA, air cells were bigger and irregular, and starch matrix was unstable. There were no significant difference in sour and bitter taste. The scores of stickiness of the 2∼4% LCA-breads were similar to that of the control and higher in the 8% LCA-bread. The scores of the flavor and overall taste in the LCA-breads were similar to the control, while the values were lower in the 4∼8% LCA-breads. The shelf-life evaluated by the number of moldy spots was not different between the control and 2% LCA-bread, while it was extended two times in 4% and three times in the 8% LCA-bread.ead.