• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.96-102
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• 2002

The purpose of this study was estimate the optimal phosphorus and calcium levels of Korean native cow manure on the growth and cast production of earthworm(Eisenia foetida). Phosphorus and calcium levels supplemented to cow manure were 0%(without earthworm), 2% and 4%, and 0.01%, 0.02%, 0.04% and 0.06% of the cow manure by weight, respectively. The maximum fresh weight and increasing rate of earthworm were obtained with 2% phosphorus level, but there was not significant differences between calcium levels. The ratios of available phosphorus to calcium contents of cast were 1.04-1.20:1 with 2%, and 1.28-1.37:1 with 4% phosphorus levels. Conversion rate of organic matter to earthworm tissue were 0.35-0.41% with 2%, and 0.25-0.40% with 4% phosphorus levels.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.19-22
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• 2017

This study was conducted to investigate the effect of acetic acid and citric acid treatments on amount and content ratio of calcium (Ca) and phosphorus (P) which were extracted from beef shank bones. The amount of Ca in shank bone extracts significantly increased with increasing citric acid and acetic acid concentration, whereas the amount of P increased with only adding citric acid to extraction media. In the case of combined treatment with 0.2 % acetic acid and 0.1 % citric acid, the amounts of Ca and P increased to 30 and 400 %, respectively and Ca and P ratio were drastically improved from 7.53 to 1.85 compared with treatment of 0.2 % acetic acid. The sensory score of shank bone extract prepared with 0.2 % acetic acid and 0.1 % citric acid treatment showed the highest values in taste and overall acceptability among the tested shank bone extracts.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.8-14
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• 2008

The effects of calcium type catalysts addition on the thermal decomposition of low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) resin have been studied in a thermal analyze. (TGA, DSC) and a small batch reactor. The calcium type catalysts tested were calcinated dolomite, lime, and calcinated oyster shell. As the results of TGA experiments, pyrolysis starting temperature for LDPE varied in the range of $330{\sim}360^{\circ}C$ according to heating rate, but EVA resin had the 1st pyrolysis temperature range of $300{\sim}400^{\circ}C$ and the 2nd pyrolysis temperature range of $425{\sim}525^{\circ}C$. The calcinated dolomite enhanced the pyrolysis rate in LDPE pyrolysis reaction, while the calcium type catalysts reduced the pyrolysis rate in EVA pyrolysis reaction. In the DSC experiments, addition of calcium type catalysts reduced the melting point, but did not affect to the heat of fusin. Calcinated dolomite reduced 20% of the heat of pyrolysis reaction. In the batch system experiments, the mixing of calcinated dolomite and lime enhanced the yield of fuel oil, but did not affect to the distribution of carbon numbers.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.319-324
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• 1990

The effects of pH, protein and fat content, addition of emulsifiers, stabilizer, sugar, salt and calcium salt on the stability of soymilk suspension were investigated by analyzing the cream separated and precipitates of soymilk which is prepared by various conditions. In the alkaline region of pH, soymilk showed a good stability of the suspension and particularly, above pH 10, precipitates were not formed. When 1.5% of palm oil with 0.4% of glycerine monostearate was added to soymilk in the hydrophile-lipophile balance (HLB) value of 4 to 7, resulted maximal emulsion stability occured below H LB 6. The stability was decreased with increasing the fat concentration and soy oil showed better emulsion stability than that of palm oil. Among the commercial stabilizers, 0.03% of carrageenan was most effective. The stability was not decreased by addition of sugar up to 3% while it was decreased by addition of sodium salt and calcium salt at low level.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.149-159
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• 1998

To utilize the oyster shell containing a lot of calcium, we investigated the bioavailability of calcium compounds from oyster shell. First, calcium oxide was prepared by burning of oyster shell at $1200^{\circ}C$. Its purity was approximately $98.5\%$. Calcium compounds, $CaCl_2$, and $CaHPO_4$, from the calcium oxide were prepared by chemical reaction. Effect on calcium absorption by the calcium compounds from oyster shell was improved using fish skin gelatin peptides.(FSGP), which was prepared by enzymatic hydrolysis of fish skin gelatin for 4hr with tuna pyloric caeca crude enzyme (TPCCE). in vitro experiment, calcium absorption by addition of FSGP in a mixture solution of calcium and phosphate was higher approximately $70\%$ than that by control. in vivo using calcium deficient rats, a group taken the diets with $3\%$ FSGP and $CaHPO_4$ was significantly improved amount of calcium and ash in femur and strength of femur. These results suggest that calcium compounds from oyster shell and FSGP could be used as an effective dietary calcium source.

• Cement Symposium
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• no.27
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• pp.14-20
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• 2000

• Polymer(Korea)
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• v.34 no.1
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• pp.38-44
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• 2010

Core-shell particles of inorganic/organic pair were synthesized from $CaCO_3$ absorbed sodium dodecyl benzene sulfonate(SDBS) surfactant. Shell components were synthesized by sequential emulsion polymerization. Various monomers were used as shell components such as methyl methacrylate(MMA), ethyl acrylate(EA), butyl acrylate(BA), and styrene(St). Ammonium persulfate(APS) was used as an initiator and 2-ethylhexyl acylate(2-EHA) was used as a functional monomer, In the $CaCO_3$/organic core-shell particle polymerization, $CaCO_3$ absorbed surfactant SDBS of 0.5 wt% was prepared first and then core $CaCO_3$ was encapsulated by emulsion polymerization. 0.1 wt% of APS was added sequentially to minimize the formation of new monomer particle during shell polymerization. The structure of inorganic/organic core-shell particles were characterized by measuring the decomposition degree of $CaCO_3$ using HCl solution, thermogravimetric analyzer, scanning electron microscope, and transmission electron microscope.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.213-219
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• 2009

Crystallization experiments were performed by addition of various amino acids into biomineralization mixture of calcium carbonate. Liquid-liquid reaction of calcium carbonate was investigated by mixing calcium chloride, sodium carbonate and additives such as silk fibroin, asparagine, aspartic acid, glutamic acid and glycine. Also, the effects of reaction time, pH and solution concentration were observed. Analysis of crystals was done by FE-SEM, XRD, FT-IR equipments. FE-SEM was used in order to analyze morphology and crystal size. XRD was used to measure peak intensities and presence of $CaCO_3$ crystal. Two kinds of crystals were confirmed by FT-IR spectrum. Crystal distribution with reaction time was identified with measured peak areas of XRD and FT-IR data.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.201-201
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• 2005

• Journal of the Korean Ceramic Society
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• v.33 no.5
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• pp.519-523
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• 1996

Calcium hydroxide produced by cement hydration decreases the durability and the compressive strength of cement mortars. Pozzolanic property of meta kaolin and silica fume allows to avoid this drawback. Calcium hydroxide consumption according to pozzolanic raction is evaluated by Fourier differential thermal analysis. Particulary the properties of high performance and high strength of cement mortar containing above 10% meta kaolin and silica fume were resulted in the pozzolanic activity.