• 한국해양학회지
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• v.10 no.2
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• pp.45-50
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• 1975

Over 50 carbonate samples were collected from the Geumgeri coast, Jin Island Textural characters, percent calcium carbonate and nature of the carbonate sediment were determined. Apparently the carbonate beach sediments were derived from the adjacent nearshore. The carbonate sediments contain over 90 percent of molluscan sheel particles, especially oyster shell fragments. The volumetric contribution of the shell fragment to the carbonate sediments is so large that the pre-existed oyster-reef like banks in the nearshore off the Geumgeri coast, Jin Island represent a spectacular example of carbonate sedimentary processes.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.3
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• pp.83-89
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• 1999

Bast fibers of paper mulberry ( Broussonetia Kazinoki Sieb) were cooked with a weak alkaline salt, potassium carbonate which has been known as a major inorganic component of the traditional lye, and its cooking characteristics were investigated . The bast fiber was easily cooked by potassium carbonate. The pulp yield was rapidly decreased up to 20-30 mol of potassium carbonate, but the Kappa number was slowly decreased with increasing of potassium carbonate. The potassium carbonate pulps were easily defibered at low cooking chemical charge of 25mm on and high pulp yield of about 80%. These results were confirmed that pectin was easily removed during the potassium carbonate cooking. In contrast, when sodium carbonate was used as a cooling agent, the bast fiber was only partially defibered. Thus, sodium carbonate was a less effective cooling chemical of the bast fiber. The results of this experiment indicated that potassium carbonate could not only be used as a good cooling agent of bast fiber, but also as an alternative agent of sodium hydroxide.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.5
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• pp.480-483
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• 2004

Butylene carbonate(4-ethyl-l,3-dioxolan-2-one), one of the cyclic carbonate was synthesized by the thermal degradation of poly(butylene carbonate). The poly(butylene carbonate) was made from 1,2-Epoxybutane and carbon dioxide which is one of the main green house gas. The prepared cyclic carbonate was identified by GC-Mass. This synthetic method is an alternative way to prepare cyclic carbonates.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.1
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• pp.16-23
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• 2021

Lithium carbonate recovered from the waste solution generated during the lithium secondary battery manufacturing process contains heavy metals such as cobalt, nickel, and manganese. In this study, the recrystallization of lithium carbonate was performed to remove heavy metals contained in the powder and to increase the purity of lithium carbonate. First, the leaching efficiency of lithium carbonate according to pH in the aqueous hydrochloric acid solution was examined, and the effect on the recrystallization of lithium carbonate according to the equivalent and concentration of sodium carbonate was confirmed. As the equivalent and concentration of sodium carbonate increased, the recovery rate of lithium carbonate improved. And the SEM image showed that the crystal shape was changed depending on the reaction conditions with sodium carbonate. Finally, the high purity lithium carbonate of 99.9% or more was recovered by washing with water.

• Environmental Mutagens and Carcinogens
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• v.19 no.1
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• pp.20-27
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• 1999

In order to know the inhibitory effect of magnesium carbonate(MgCO3) on cytotoxicity, DNA damage, mutagenicity, and cell transforming ability of nickel subsulfide, the inhibition of cell proliferation, DNA-protein crosslinks formation (DPC), HGPRT point mutation, and cell transformation were evaluated. Nickel subsulfide(Ni3S2) and magnesium carbonate as insoluble compounds were used for this study. BALB/3T3 cell, CHO-K1 cell, and C3H10T1/2 cell were used in this experiment. Exposure concentration of nickel subsulfide was 1 $\mu\textrm{g}$/ml. The concentrations of magnesium carbonate in this study were 0.6 $\mu\textrm{g}$/ml, 1.2 $\mu\textrm{g}$/ml, 2.4 $\mu\textrm{g}$/ml and the molar ratio of magnesium to nickel when exposed simultanously were 0.5, 1.0 and 2.0 respectively. The results were as follows; 1. Magnesium carbonate reduced the inhibitory effect of nickel subsulfide on cell proliferation. 2. Magnesium carbonate also reduced the effect of nickel subsulfide on DNA-protein crosslinks formation. 3. HGPRT point mutagenicity of nickel subsulfide was reduced when magnesium carbonate treated simultaneously. 4. Magnesium carbonate reduced cell transforming ability of nickel subsulfide. Conclusively, nickel subsulfide showed cytotoxicity, cell transforming ability, and mutagenicity strongly and magnesium carbonate may have protective roles in these nickel effects.

• Journal of Pharmaceutical Investigation
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• v.17 no.2
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• pp.95-98
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• 1987

The drug interaction between probenecid and lithium carbonate was studied pharmacokinetically in rabbits. The blood level and the area under the concentration curve (AUC) of lithium carbonate administered orally were elevated by coadministration of probenecid. Probenecid inhibited the urinary excretion of lithium carbonate in rabbits. Biological half-life and $t_{max}$ of lithium carbonate were prolonged by coadministration of probenecid. From these results, dosage regimen of lithium carbonate is considered to be adjusted for effective and safe therapy in the coadministration of probenecid.

• Bulletin of the Korean Chemical Society
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• v.7 no.1
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• pp.70-73
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• 1986

New amino protective reagents, t-butyl benzotriazol-1-yl carbonate and benzyl benzotriazol-1-yl carbonate, for t-butoxycarbonylation and benzyloxycarbonylation of amines and amino acids have been developed. t-Butyl benzotriazol-1-yl carbonate reacts rapidly and cleanly with various amines and amino acids to afford N-Boc amines and N-Boc amino acids in high yields and benzyl benzotriazol-1-yl carbonate is also found to be very effective in the benzyloxycarbonylation of amino acids.

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.121-126
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• 1989

Two kinds of solution for the measurement of solubilities of Sericin are prepared as followings at temperature 90 deg. C. One has the total carbonate concentration as 0, 50, 100mg CO2/l prepared with non-carbonate distilled water, sodium hydrogen carbonate and 0.1N HCI and NaOH, the other has total hardness, that is, calcium hardness or magnesium hardness as 0, 20, 50, 100mg CaCO2/l respectively prepared with non-carbonate distilled water, calcium carbonate and magnesium oxide. Solubilities of Cocoon layer Sericin at above solution gives following results ; 1. pH shows little effect on the solubility of Sericin at the non-carbonate solution but at the carbonate solution pH shows a sensitive effect on the solubility of Sericin. These means that pH controls the concentration of H2CO3, HCO3-and CO32- which prevent and promote the solution of Sericin. 2. After the cocoon layer treatment at the solution, the initial pH of 4.0, 7.0, 9.0 of the solution changed to 6.0-6.5 at the lower total carbonate solution. However in the higher total carbonate solution pH did not changed very much. This may be explained by the buffer action of carbonate. 3. The effect of the hardness on the solubility of Sericin was not found in the non-carbonate solution with the standard hardness after treatment of cocoon layer.

• Fibers and Polymers
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• v.3 no.1
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• pp.1-7
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• 2002

Cellulose carbonate was prepared by the reaction of cellulose pulp and $CO_2$ with treatment reagents, such as aqueous $Zncl_2$ (20-40 wt%) solution, acetone or ethyl acetate, at -5-$0^{\circ}C$ and 30-40 bar ($CO_2$) for 2 hr. Among the treatment reagents, ethyl acetate was the most effective. Cellulose carbonate was dissolved in 10% sodium hydroxide solution containing zinc oxide up to 3 wt% at -5-$0^{\circ}C$. Intrinsic viscosities of raw cellulose and cellulose carbonate were measured with an Ubbelohde viscometer using 0.5 M cupriethylenediamine hydroxide (cuen) as a solvent at $20^{\circ}C$ according to ASTM D1795 method. The molecular weight of cellulose was rarely changed by carbonation. Solubility of cellulose carbonate was tested by optical microscopic observation, UV absorbance and viscosity measurement. Phase diagram of cellulose carbonate was obtained by combining the results of solubility evaluation. Maximum concentration of cellulose carbonate for soluble zone was increased with increasing zinc oxide content. Cellulose carbonate solution in good soluble zone was transparent and showed the lowest absorbance and the highest viscosity. The cellulose carbonate and its solution were stable in refrigerator (-$5^{\circ}C$ and atmospheric pressure).

• Journal of the Korean Society of Food Culture
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• v.13 no.4
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• pp.261-266
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• 1998

In an attempt to evaluate the effects of alkali agents on properties of Ramyon, cooking quality, textural and sensory properties were examined. The shear extrusion force of Ramyon made from sample A(potassium carbonate 64%, sodium carbonate 14%, sodium pyrophosphate 2% and sodium metaphosphate 20%), sample B(potassium carbonate 31%, sodium carbonate 39% , sodium pyrophosphate 1%, sodium metaphosphate 15%, sodium polyphosphate 8%, sodium phosphate monobasic 4% and sodium phosphate dibasic 2%), sample C(potassium carbonate 60%, sodium carbonate 33% and sodium pyrophosphate 7%), and sample D(potassium carbonate 44%, sodium carbonate 27%, sodium metaphosphate 27% and sodium polyphosphate 2%) were 12.80(kgf), 10.35(kgf), 9.05(kgf) and 8.45(kgf), respectively, but that of control I was 5.24(kgf). The hardness of Ramyon manufactured with sample A, B, C and D were 18.57(kgf), 16.48(kgf), 14.26(kgf) and 12.34(kgf), respectively, but that of control I was 11.23(kgf). At cooking quality examination of Ramyon made from several alkali agents, weight of cooked Ramyon was increased but volume was appeared in vice versa. Extraction amounts of Ramyon manufactured with several alkali agents during cooking were from 35% to 38%, but that of control I was 70%. These changes will provided many advantages in the preparation of Ramyon. The $I_2$ reaction value(${\alpha}-degree$ of noodle) of Ramyon manufactured with several alkali agents and control were shown to almost same values, from 2.10 to 2.20. Sensory properties of cooked Ramyon which was manufactured with several alkali agents showed quite acceptable.