• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.3
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• pp.91-99
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• 2016

The objective of this study was to investigate characteristics of inorganic components contained in liquid fertilizer produced using fish meal under different condition. Addition of dry yeast to liquid fertilizer resulted in considerable change in pH and electrical conductivity(EC) value compared to other liquid fertilizers which have microorganisms additives. In addition, it was appeared that the dry yeast-added treatment had higher $NH_4-N$ concentration than other treatments. Addition of molasses resulted in low pH compared to the control which has no additives. The EC, concentration $NH_4-N$ and $P_2O_5$ were not significant difference according to addition of molasses. The pH and $NH_4-N$ concentration in liquid fertilizer containing 20% of fish meal was highest after fermentation process, and EC value increased as the content of fish meal increase. When Cucumber was cultivated using liquid fertilizer, there was no difference in growth between fish meal liquid fertilizer treatment and chemical fertilizers treatment. However, there was a difference in yield according to the supply amount of nitrogen during the growing season.

• Membrane and Water Treatment
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• v.2 no.4
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• pp.207-223
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• 2011

Supported Liquid Membranes (SLMs) have been widely studied as feasible alternative to traditional processes for separation and purification of various chemicals both from aqueous and organic matrices. This technique offers various advantages like active transport, possibility to use expensive extractants, high selectivity, low energy requirements and minimization of chemical additives. SLMs are not yet used at large scale in industrial applications, because of the low stability. In the present paper, after a brief overview of the state of the art of SLM technology the facilitated transport mechanisms of SLM based separation is described, also introducing the small and the big carrousel models, which are employed for transport modeling. The main operating parameters (selectivity, flux and permeability) are introduced. The problems related to system stabilization are also discussed, giving particular attention to the influence of membrane materials (solid membrane support and organic liquid membrane (LM) phase). Various approaches proposed in literature to enhance SLM stability are also reviewed. Modification of the solid membrane support, creating an additional layer on membrane surface, which acts as a barrier to LM phase loss, increases system stability, but the membrane permeability, and then the flux, decrease. Stagnant Sandwich Liquid Membrane (SSwLM), an implementation of the SLM system, results in both high flux and stability compared to SLM. Finally, possible large scale applications of SLMs are also reviewed, evidencing that if the LM separation process is opportunely carried out (no production of byproducts), it can be considered as a green process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.808-815
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• 2008

The composites were fabricated 61[vol.%] ${\beta}$-SiC and 39[vol.%] $TiB_2$ powders with the liquid forming additives of 8, 12, 16[wt%] $Al_2O_3+Y_2O_3$ as a sintering aid by pressureless annealing at 1650[$^{\circ}C$] for 4 hours. The present study investigated the influence of the content of $Al_2O_3+Y_2O_3$ sintering additives on the microstructure, mechanical and electrical properties of the pressureless annealed SiC-$TiB_2$ electroconductive ceramic composites. Reactions between SiC and transition metal $TiB_2$ were not observed in the microstructure and the phase analysis of the pressureless annealed SiC-$TiB_2$ electroconductive ceramic composites. Phase analysis of SiC-$TiB_2$ composites by XRD revealed mostly of ${\alpha}$-SiC(6H), ${\beta}$-SiC(3C), $TiB_2$, and In Situ YAG($Al_2Y_3O_{12}$). The relative density of SiC-$TiB_2$ composites was lowered due to gaseous products of the result of reaction between SiC and $Al_2O_3+Y_2O_3$. There is another reason which pressureless annealed temperature 1650[$^{\circ}C$] is lower $300{\sim}450[^{\circ}C]$ than applied pressure sintering temperature $1950{\sim}2100[^{\circ}C]$. The relative density, the flexural strength, the Young's modulus and the Vicker's hardness showed the highest value of 82.29[%], 189.5[Mpa], 54.60[Gpa] and 2.84[Gpa] for SiC-$TiB_2$ composites added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at room temperature. Abnormal grain growth takes place during phase transformation from ${\beta}$-SiC into ${\alpha}$-SiC was correlated with In Situ YAG phase by reaction between $Al_2O_3$ and $Y_2O_3$ additive during sintering. The electrical resistivity showed the lowest value of 0.0117[${\Omega}{\cdot}cm$] for 16[wt%] $Al_2O_3+Y_2O_3$ additives at 25[$^{\circ}C$]. The electrical resistivity was all negative temperature coefficient resistance (NTCR) in the temperature ranges from $25^{\circ}C$ to 700[$^{\circ}C$]. The resistance temperature coefficient of composite showed the lowest value of $-2.3{\times}10^{-3}[^{\circ}C]^{-1}$ for 16[wt%] additives in the temperature ranges from 25[$^{\circ}C$] to 100[$^{\circ}C$].

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.641-644
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• 2001

This study was performed for development of new analytical method of monascus pigments in foods. In this method, analysis of monascus pigment in foods has been carried out by detection of monascin and ankaflavin of the main color component of monascus pigment as indicator compounds. Monascin and ankaflavin were isolated and identified by TLC, HPLC, Prep. HPLC, $^{1}H-NMR$ and Mass spectrophotometer. The analysis of monascin and ankaflavin in foods such as massal, sausage, mixed press ham, mixed fish sausage, semi-dried sausage and syrup was performed by using reverse phase high performance liquid chromatograph with Capcell Pak C18 column at wave length 390 nm. The quantitative results of monascin were as follows : $0.01{\sim}3.31\;{\mu}g/g$ item in massal, $0.05{\sim}0.10\;{\mu}g/g$ in mixed fish sausage, and $0.34{\sim}0.35\;{\mu}g/g$ in semi-dried sausage. But the quantitative results of ankaflavin were as follows: $0.02{\sim}0.89\;{\mu}g/g$ in massal, ankaflavin were not founded in other samples.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.162-165
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• 2006

In this study, Liquid Phase Sintered SiC (LPS-SiC) was fabricated by hot pressing method with $\beta$-SiC powder whose a particle size is 30nm and less on the average in argon condition at 1780 and $1800^{\circ}C$ under 20MPa. Alumina ($Al_2O_3$), yttria ($Y_2O_3$) and silica ($SiO_2$) were used for sintering additives. To investigate effects of particle-size and temperature on $SiO_2$, LPS-SiC was fixed $Al_2O_3$, $Y_2O_3$ and then particle-size of $SiO_2$ were changed as two kinds. The system of particle-size and temperature on sintering additives which affects a property of sintering os well os the influence depending on particle-size and temperature of sintering additives were investigated by measurement of sintering properties. Such as measurement of sintering density, vikers hardness and observing of microstructure were investigated to make sure of the optimum condition which is about matrix of $SiC_f/SiC$ composites. Base on the composition of sintering additives, microstructure and sintering property correlation, the effect of particle-size of sintering additives are discussed. An experimental method to investigate the dynamic characteristics of bums in extreme environmental condition is established.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.7
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• pp.394-399
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• 2000

The mechanical and electrical properties of pressed and annealed $\beta-SiC-TiB_2$ electroconductive ceramic composites were investigated as a function of the liquid forming additives of $Al_2O_3+Y_2O_3$. Phase analysis of composites by XRD revealed $\alpha$-SiC(6H), TiB2, and (Al5Y3O12). Reaction between Al2O3 and $Y_2O_3$ formed YAG but the relative density decreased with increasing $Al_2O_3+Y_2O_3$ contents. The Flexural strength showed the value of 458.9 MPa for composites added with 4 wt% $Al_2O_3+Y_2O_3$ additives at room temperatures. Owing to crack deflection and crack bridging, the fracture toughness showed 6.2, 6.0 and 6.6 MPa.m1/2 for composites added with 4, 8 and 12 wt% Al2O3+Y2O3 additives respectively at room temperature. The resistance temperature coefficient showed the value of $3.6\times10^{-3},\; 2.9\times10^{-3}\; and\; 3.0\times10^{-3} /^{\circ}C$$^{\circ}C$ for composite added with 4, 8 and 12 wt% $Al_2O_3+Y_2O_3$additives respectively at room temperature. The electrical resistivity of the composites was all positive temperature coefficient resistance(PTCR) in the temperature range of $25^{\circ}C\; to\; 700^{\circ}$.

• Journal of the Korean Ceramic Society
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• v.42 no.8 s.279
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• pp.542-547
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• 2005

Keys to the attainment of tailored properties in SiC ceramics are microstructure control and judicious selection of the sintering additives. In this study, three different strategies for controlling microstructure of liquid-phase-sintered SiC ceramics (LPS-SiC) have been suggested: control of the initial $\alpha-SiC$ content in the starting powder, a seeding technique, and a post-sintering heat treatment. The strategies suggested offer substantial flexibility for producing toughened SiC ceramics whereby grain size, grain size distribution, and aspect ratio can be effectively controlled. The present results suggest that the proposed strategies are suitable for the manufacture of toughened SiC ceramics with improved toughness.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.1
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• pp.55-63
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• 2009

In this study, thermochemical degradation by acetone solvolysis reaction of siberian spruce wood was investigated for a temperature range of $200{\sim}400^{\circ}C$. The liquid products by acetone solvolysis from siberian spruce wood produced various kinds of aliphatics, cyclic compounds and aromatics included phenols etc. Combustion heating value of liquid products by acetone solvolysis conversion processes was in the range of $8,010{\sim}8,180cal/g$. The energy yield in acetone solvolysis of siberian spruce wood was as high as 74.2% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce wood could be used as high-octane-value fuels and fuel additives.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.5
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• pp.430-438
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• 2008

Siberian spruce, found in the northern temperature and boreal regions of the earth, is usable biomass as fuels. In this study, parameters of thermochemical degradation by pyrolysis-liquefaction reaction of siberian spruce such as the effect of reaction temperature, reaction time and degradation products and energy yields were investigated. The liquid products from pyrolysis-liquefaction of siberian spruce contained various kinds of cyclicketones, cresols, dimethyl phenols and benzenediols. Combustion heating value of liquid products from pyrolysis-liquefaction conversion processes was in the range of $7,650{\sim}7,800cal/g$. The energy yield in pyrolysis-liquefaction of siberian spruce was as high as 69.5% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce could be used as high octane value fuels and fuel additives.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1821-1826
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• 2009

Liquid crystal display (LCD) devices contain a colour filter which can visualise colour images by transmitting or absorbing light. Colour properties of LCD mainly depend on colour materials such as pigments and polymeric binders. In this paper, colour properties were studied to improve colour quality of LCD. Generally, the colour properties can be classified into three categories which are colour purity, brightness and contrast ratio. For this study, photo resists were prepared by treatment of pigments and synthesis of polymeric binder. The treated pigments were dispersed and formulated with additives for preparing a photo resist that could be used for manufacturing colour filters. As a result of what we studied, type, mixture ratio and concentration of pigments were very important to improve colour purity of LCD device.