• The Korean Journal of Ceramics
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• v.4 no.4
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• pp.292-296
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• 1998

In wet powder processing of alumina, a number of organic molecules such as dispersant and binder are used to produce the flow behavior and properties requisite for shape forming. In this study, interparticle forces of alumina particles suspended in aqueous media were controlled by suspension pH, poly (methacrylic acid) (PMAA, used as dispersant) and poly (vinyl alcohol) (PVA, used as binder). The combined adsorption isotherms of the dispersant and binder additives on alumina were determined by total organic carbon analyzer, while the adsorption of dispersant was differentiated from binder in the mixed additive system by ultraviolet spectroscopy. The electrokinetic behavior of alumina suspensions were then correlated with the adsorption characteristics of dispersant and binder onto alumina particles. It was found that the isoelectric ($pH_{iep}$) of alumina shifted from pH 8.9${\pm}$0.1 to acidic pH as PMAA concentration increased, while PVA adsorption did not affect the $pH_{iep}$ but caused a decrease in the near surface potential.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.3
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• pp.245-249
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• 2011

Carbon nanotubes (CNTs) have been significantly used for the field emitters for display applications. However, the lifetime of CNT emitters which are formed by screen printing technique is not guaranteed yet, because the constituents in CNT paste affect the lifetime of CNTs. The CNT pastes for screen printing are normally composed of organic vehicles (nitro cellulose, ethyl cellulose, etc) and additives (glass frits, indium tin oxide (ITO), etc) with CNTs. In this study, the effects of constituents in CNT pastes on the lifetime and emission characteristics of CNTs were investigated by thermal and electrical analysis. Use of glass frits worsened the lifetime and electron emission of CNTs. However, an addition of ITO to CNT paste rather improved the lifetime of CNTs. Degradation of CNTs was small when nitro cellulose was used in CNT paste as an organic vehicle.

• Journal of Integrative Natural Science
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• v.4 no.1
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• pp.15-22
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• 2011

In this study, liquid with carbonized artemisia was developed for the first time that can be used as food additives and outside medicinal agents by burning artemisia species such as Artemisia dubia wall, Artemisia capillaris Thunb, Artemisia montana (Nakai) Pamp), Artemisia keiskeana Miq, Leonurus Japonicus Houtt. etc. In addition, edibility of recovered liquid with carbonized artemisia was verified by comparing the contents according to each ingredient with common refined pyroligneous liquid through the analysis of 9 kinds of organic acid by the species of artemisia, methanol and ethanol. Besides, the result of antimicrobial activities on six kinds of food spoilage and food poisoning bacteria observed by paper disc method for liquid with carbonized artemisia indicated that those two liquids showed strong antimicrobial. At the concentration of 1.5 mg/disc, clear zone for S. sonnei and S. aureus, L. monocytogenes was 13~16 mm, and they showed stronger antimicrobial activities than other strain.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1291-1298
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• 2002

To utilize coastal aquaculture ground bottom sediment in which concentrations of harmful pollutants are low and organic content is high as an organic fertilizer alkaline stabilizers such as CaO, Oyster shell, Mg(OH)$_2$ were added to the bottom sediment organic additives of livestock or food wastes. Nutritive qualities of crude fertilizers were measured to examine effects of alkaline stabilizers and organic waste additions. The Mg(OH)$_2$-added crude fertilizer had significantly lower total carbon(T-C) and nitrogen(T-N) content, reflecting the dilution effect due to great amount of Mg(OH)$_2$ addition. However, the addition of oyster shell had no significant effect on the T-C and T-N content of the fertilizer. $P_2O_5$ and $K_2$O content was considerably higher in the mixed sample of aquaculture ground bottom sediments and livestock wastes than in the mixture of the sediments and food wastes, resulting from higher $P_2O_5$ and $K_2$O content in livestock wastes. Addition of Mg(OH)$_2$ increased the content of MgO In the crude fertilizer but significantly reduced the content of other nutritive elements such as $P_2O_5$, $K_2$O and CaO. Addition of oyster shell as an alkaline stabilizer seemed to have the advantage of saving time and expenses far dryness due to its role as a modulator of water content. Moreover, additions of effect Mg(OH)$_2$ decreased the concentrations of heavy metals in the fertilizer by the dilution while additions of oyster shell had no influence on heavy metal concentrations in the fertilizer.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.501-514
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• 2018

Taraxacum hallaisanense (pr), a species of the family Compositae is a perennial herb plants that inhabit to Jeju Island. In the study, we performed to determine the anti-inflammatory effects in LPS-induced RAW 264.7 cells and antioxidant activity of ethanol extracts from T. hallaisanense whole plants. The antioxidant activity of extracts was measured by contents of polyphenol and flavonoid, DPPH radical scavenging, and reducing power activity. The anti-inflammatory effect of T. hallaisanense extracts was measured by NO and $IL-1{\beta}$ production inhibitory activity and the expression of pro-inflammatory in lipopolysaccharide (LPS)-induced Raw 264.7 cells. Also, the expression of pro-inflammatory genes such as iNOS, COX-2 and NF-kB protein were reduced. In the cytotoxicity measurement by cytotoxicity kit, the extract was exhibited Raw 264.7 cell viabilities as nontoxic result in concentration of $25{\sim}400{\mu}g/ml$. These results indicated that ethanol extracts of T. hallaisanense whole plants expected development possibility as nutrial additives through high anti-inflammatory effects and antioxidant activity.

• Journal of Powder Materials
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• v.27 no.2
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• pp.146-153
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• 2020

The co-doping effect of aliovalent metal ions such as Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, and Zn²⁺ on the photoluminescence of the Y₂O₃:Eu³⁺ red phosphor, prepared by spray pyrolysis, is analyzed. Mg²⁺ metal doping is found to be helpful for enhancing the luminescence of Y₂O₃:Eu³⁺. When comparing the luminescence intensity at the optimum doping level of each Mg²⁺ ion, the emission enhancement shows the order of Zn²⁺ ≈ Ba²⁺ > Ca²⁺ > Sr³⁺ > Mg²⁺. The highest emission occurs when doping approximately 1.3% Zn²⁺, which is approximately 127% of the luminescence intensity of pure Y₂O₃:Eu³⁺. The highest emission was about 127% of the luminescence intensity of pure Y₂O₃:Eu³⁺ when doping about 1.3% Zn²⁺. It is determined that the reason (Y, M)₂O₃:Eu³⁺ has improved luminescence compared to that of Y₂O₃:Eu³⁺ is because the crystallinity of the matrix is improved and the non-luminous defects are reduced, even though local lattice strain is formed by the doping of aliovalent metal. Further improvement of the luminescence is achieved while reducing the particle size by using Li₂CO₃ as a flux with organic additives.

• Journal of the Korean Ceramic Society
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• v.41 no.4
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• pp.277-283
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• 2004

To fabricate green sheet of transparent dielectric for PDP front panel, dispersion of transparent dielectric slurry, density, and mechanical properties of green sheets have been investigated as a function of amount and composition of organic additives. Measurements of sedimentation and viscosity were employed to determine a proper dispersant and its amount for a well dispersed transparent dielectric powders in non-aqueous system. Green sheets, having various ratios of transparent dielectric powders to transparent dielectric powders＋ binder＋plasticizer and binder to binder＋plasticizer, were fabricated. All the tape casting slurries showed shear thinning effect, that is, the apparent viscosity decreased with the increase of shear rate. It was found that the amount and composition of organic additives were main variables to affect densities and mechanical properties of transparent dielectric green sheets for PDP.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.21-34
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• 1995

For development of microbial additives applicable to in-vessel composting system of food waste, thermophilic bacteria which showed amylase, protease, lipase and cellulase activity were isolated from soil, compost and food waste. Among 81 isolates, the growth characteristic of 20 strains with high enzyme activity were examined. All strains are Gram positive rod with catalase activity and 17 strains are spore formers. At $50^{\circ}C$, most of the strains were able to grow from pH 5 to pH 10 and in presence of 8% of NaCl. In trypticase soy broth, the growth of these strains was greatly increased by aeration, but decreased at elevated temperature above $50^{\circ}C$.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.431-437
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• 2019

The purpose of this study is to develop an organic-inorganic hybrid insulation materials which has an economic feasibility of organic level and excellent adiabatic performance and fire stability by impregnating organic materials with inorganic binder solutions. The organic base was commercial polyurethane sponge, and the inorganic binder slurry was prepared by mixing water and additives into recycled gypsum byproducts. As a result of evaluation of the developed materials, it was confirmed that it not only has excellent insulation performance of a thermal conductivity of 0.051 W/mK or less but also it is a semi-non-combustible materials specified in the Ministry of Land, Infrastructure and Transport Notice No. 2015-744. The developed materials can also be controlled for thermal conductivity and flame retardance according to density control during manufacturing process, and thus it can be applied to various insulation materials.

• Transactions on Electrical and Electronic Materials
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• v.17 no.3
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• pp.134-138
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• 2016

The fullerene solar cells are becoming a feasible choice due to the advanced developments in donor materials and improved fabrication techniques of devices. Recently, sufficient optimization and improvements in the processing techniques like incorporation of solvent vapor annealing (SVA) with additives in solvents has become a major cause of prominent improvements in the performance of organic solar cell-based devices . On the other hand, the challenge of reduced open circuit voltage (V_oc) remains. This study presents an approach for significant performance improvement of overall device based on organic small molecular solar cells (SMSCs) by following a two step technique that comprises thermal annealing (TA) and SVA (abbreviated as SVA+TA). In case of exclusive use of SVA, reduction in V_oc can be eliminated in an effective way. The characteristics of charge carriers can be determined by the measurement of transient photo-voltage (TPV) and transient photo-current (TPC) that determines the scope for improvement in the performance of device by two step annealing. The recovery of reduced V_oc is linked with the necessary change in the dynamics of charge that lead to increased overall performance of device. Moreover, SVA and TA complement each other; therefore, two step annealing technique is an appropriate way to simultaneously improve the parameters such as V_oc, fill factor (FF), short circuit current density (J_sc) and PCE of small molecular solar cells.