• Journal of the Korean Graphic Arts Communication Society
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• v.21 no.1
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• pp.1-10
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• 2003

Printing ink is faced various shear stress situation until it transfer to the printed substrate through the press. And in each shear stress condition the ink is needed to keep the appropriate viscosity according to the condition. The change of printing ink viscosity has been explained by well-known through the viscosity profile curve. But actually, the quality of printed paper depends on the ink behavior after transfer the substrates. Like this, to look into the behaviour of the ink on the printed substrate, it is needed the experiment of the ink structure recovering by rheology study. In this study, by controling the $CaCO_3$ content in the ink, after investigating the effect of the ink's structure recovery of the pigment concentration, we intend to predict the printing quality of the ink behvior on the substrate depending on pigment content.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.134-141
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• 2015

The focus of this study was to observe the growth of Chlorella vulgaris and Botryococcus braunii under mixotrophic conditions (i.e., added acorn) with the aim of increasing biomass and triacylglycerols (TAGs) content. The result of investigation indicated that the acorn contains a lot of carbonate (87.29%) and glucose (97.99 mg%). A significant growth of biomass was obtained when grown in acorn rich environment comparing to autotrophic conditions. 3 g/L acorn yielded the highest biomass concentration for these strains. Thus, the biomass productivity with 3 g/L acorn was obtained 2.31 times and 2.10 times higher than that of authotrophic conditions for Chlorella vulgaris and Botryococcus braunii, respectively. The maximum amount of TAGs was reached 14.35% and 18.41% for Chlorella vulgaris and Botryococcus braunii, respectively, in the growth medium with 5 g/L acorn. The effect of acorn could enhance the investigated microalgae growth, biomass productivity and TAGs content. This provides a feasible way to reduce the cost of bioenergy production from microalgae.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.28-35
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• 1983

The object of this study was to investigate the distribution of Cd fractions in paddy soils in relation to some soil characteristics and to find out the relationships between soil Cd fractions and Cd content in brown rice. Thirty six soils and rice samples were collected from the paddy field adjacent to zinc mining sites at harvest time in 1981. Total Cd content of brown rice samples was analyzed. A sequential extraction procedure was used to fractionate Cd in soils into the designated forms of exchangeable, adsorbed, organically bonded, carbonate, sulfide, and residual Cd. The results obtained were as follows: 1. The distribution of Cd fractions in soil showed a wide difference depending on soil properties. As an average value it was observed that organically bonded Cd amounted 43.7%; residual Cd, 6.5%; and other fractions, 10-15%. 2. With higher soil pH, organically bonded and carbonate Cd fraction tended to be higher but exchangeable fraction lower. Other forms of Cd showed no difference with soil reaction. 3. Organically bonded fraction was positively correlated with soil organic matter content, while others except adsorbed fraction showed an adverse tendency. 4. The relation of fraction distribution to soil C E C was similar to the case of organic matter. 5. Cadmium content in brown rice showed significant possitive correlation with organically bonded Cd content (r = 0.655) and carbonate, Cd content of soil (r = 0.328) but there was no significant correlation with contents of other forms.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.637-643
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• 2010

For enhancement of apple productivity, the calcium fertilizers to increase the calcium content of fruit, and reduce the incidence of bitter pit in apples are applied. Crushed oyster shell contains a plenty of calcium carbonate, and a very small amount of boron, ferrous, and manganese. A field study was conducted to determine the optimum level of crushed oyster shell for soil nutrient management, and its effect on the induction of bitter pit in cultivar 'Gamhong' apple. The application of crushed oyster shell increased organic matter, available phosphate, and exchangeable cation concentration in soil. We found a significant positive correlation between soil pH, and application level of crushed oyster shell in both top, and subsoils. The incidence of bitter pit in apple fruit at the harvest stage was significantly higher in non treatment and calciummagnesium carbonate treatment than on over applications 4 Mg $ha^{-1}$ for crushed oyster shell. However, the optimum level of crushed oyster shell was 2 Mg $ha^{-1}$, especially considering the soil Ca content, soil pH, fruits weight, and yield. Our results show that the crushed oyster shell can be effective in restoring the soil nutrient balance, and inducing the bitter pit in apple fruit.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.621-627
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• 2013

In order to apply eco-friendly poly(propylene carbonate) (PPC) into barrier packaging materials, six different PPC/exfoliated graphite (EFG) nanocomposite films with different EFG were successfully prepared by a solution blending method. Their water sorption behavior was gravimetrically investigated as a function of the EFG content and interpreted with respect to their chemical structure and morphology. The water sorption isotherms were reasonably well fitted by Fickian diffusion model, regardless of morphological heterogeneities. With increasing the EFG content, the diffusion coefficient and water uptake decreased from $12.5{\times}10^{-10}cm^2sec^{-1}$ to $7.2{\times}10^{-10}cm^2sec^{-1}$ and from 8.9 wt% to 4.2 wt%, respectively, which indicates that the moisture resistance capacity of PPC was greatly enhanced by incorporating EFG into PPC. The enhanced water barrier property of the PPC/EFG nanocomposite films with the high aspect ratio EFG makes them potential candidates for versatile packaging applications. However, to maximize the performance of the nanocomposite films, further researches are required to increase the compatibility of EFG in the PPC matrix.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1086-1093
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• 2012

This research was carried out to develop the correction method of VDI4630 method improving accuracy, and investigated the effects of carbonate ion ($CO_3{^{2-}}$) and reactant water ($H_2O$) on anaerobic organic biodegradability in VDI4630 method. Pig blood, pig intestine residue, pig digestive tract content, and cattle rumen content were experimented as waste biomasses. Chemical formulas of pig blood, pig intestine residue, pig digestive tract content, and cattle rumen content were $C_{3.78}H_{8.39}O_{1.46}N_1S_{0.01}$, $C_{9.69}H_{15.42}O_{2.85}N_1S_{0.03}$, $C_{25.17}H_{43.32}O_{15.04}N_1$, $C_{27.23}H_{42.38}O_{15.93}N_1S_{0.11}$, respectively. And amount of reactant moisture for the anaerobic degradation of organic materials were 0.336, 0.485, 0.227, 0.266 mol, respectively. In pig blood, pig intestine residue, pig digestive tract content, and cattle rumen content, anaerobic organic biodegradability presented as $B_u/B_{th}$ were 82.3, 81.5, 70.8, and 66.1%, and anaerobic organic biodegradability (AB) by VDI4630 method were 72.2, 87.8, 74.2, 62.0%, and that were significantly different with anaerobic organic biodegradability presented as $B_u/B_{th}$. The effects of carbonate ion and reactant water on anaerobic organic biodegradability were not significant, But Accuracy of anaerobic organic degradability was expected to able to be improved by the correction method of VDI4630 considering the carbonate ion at digestate and the reactant water quantified.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.530-534
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• 2011

The synthesis of dimethyl carbonate by liquid phase oxidative carbonylation of methanol was studied under batch reaction system. Reaction factors such as effect on various metals, anion containing in copper catalyst, temperature, carbon monoxide and oxygen molar ratio and copper content were investigated. In particular $CuCl_2{\cdot}2H_2O$ showed the excellent of the methanol conversion 65.2%, DMC selectivity 96.6% reaction condition under 1.0 g, $150^{\circ}C$, MeOH/CO/$O_2$=0.2/0.215/0.05 (molar ratio). $CuCl_2$ led to corrosion of the reactor. Thus, a new catalyst system using supports was investigated to resolve these corrosion problem. Influence on various supports were examined and copper catalyst supported on zeolite Y showed the most excellent activity on the formation of dimethyl carbonate. The amount of Fe dissolved during the reaction using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometer) was compared with catalysts, calcined Cu/zeolite Y showed the lower value below 5% than $CuCl_2-2H_2O$.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.970-976
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• 1996

An ester-carbonate copolymer was synthesized, in which carbonate was inserted into a biodegradable aliphatic polyester, poly(butylene succinate) (PBS), to modify its mechanical properties. The synthesis was carried out by condensation reactions in two steps. In the first step, oligo(butylene succinate) was prepared by the reaction of succinic acid with 1,4-butanediol (BD). In the second step, it was reacted with oligohexamethylenecarbonate diol (OHMCG) to prepare the ester-carbonate copolymer. Titanium(IV) isopropoxide (TIP) was used as a catalyst for the reaction. The structure of the copolymer was confirmed by FT-IR and $^1H$-NMR and the thermal behavior and mechanical properties were investigated by differential scanning calorimetry (DSC) and universal testing machine (UTM), respectively. It was found that optimum amount of the catalyst for the formation of high molecular weight copolymer was 1wt% for succinic acid. When the BD:OHMCG is in the range 149:1~249:1, the copolymer with high viscosity was obtained. As the OHMCG content was increased, melting temperature ($T_m$) of the copolymer was decreased. When BD:OHMCG is 149:1, the copolymer showed a increase in ultimate strain by two times and the slight decrease in modulus compared to those of PBS.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.2
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• pp.149-154
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• 1971

To elucidate the effects of calcium carbonate applied under upland and flooded conditions on the changes of soil pH, an incubation study of a soil was carried out. The experiment was conducted under the conditions with and without ground rice straw application. The results of the experiment are summarized as follows: 1. The incubation under the upland moisture condition after the application of calcium carbonate raised soil pH as high as calcium hydroxide did, whereas incubation with calos treatment under the flooded condition showed a low pH. 2. Reduction of a soil brought about by the application of ground rice straw has a significant effect on the rise of soil pH. The high pH of a soil thus brought about or raised by the use of lime is gradually reduced as the accumulation of bicarbonate ions and carbon dioxide increases in the soil solution. It may, however, be possible to keep the high pH of a flooded soil by practicing intermittent drainage or cultivation which reduces the content of bicarbonate and $CO_2$ pressure in soil solution. 3. Carbonate and bicarbonate salts which may be produced in flooded and reduced soil increases the buffering capacity of the soil.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.84-91
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• 2017

Fiber reinforced plastic (FRP) is a typical plastic composite which is fabricated using fiber reinforcement with resin to represent the high strength properties. The mechanical properties of FRP should be determined by a fibrous material, and the studies about the role of fiber as a reinforcement has been an interested subject, whereas a study along the effect of filler is not so big. However, the filler effect must be considered on the properties of the composite, because the filler influence on the plastic or resin compound which reacts as a matrix material of the composite. Thus, in this work, we studied the filler effect with size and content using $3-6{\mu}m$ of ground calcium carbonate. The specimen was prepared by sheet molding compound (SMC) method, and the mechanical properties were compared with bending strength and tensile strength. As a result, it was confirmed that the size and contents of calcium carbonate affected the strength of composites, and the condition of $2.8{\mu}m$ which was the smallest size condition showed the highest strength.