• The Korean Journal of Ceramics
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• v.5 no.3
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• pp.235-238
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• 1999

In a ceramic green body, some degree of nonuniformity in density always presents. These differences in green density will appear as nonuniform shrinkage after sintering takes place. For the complex ceramic bodies with various curves and angles, therefore, it is quite difficult to foresee the final dimensions precisely after sintering. This simulation study shows that, considering the sintering process as a thermal shrinkage phenomenon, the use of NASTRAN enables to predict the precise shape of a sintered body. Based on this result, 'the reverse engineering technique' has been developed that can unfold the exact dimensions of a green body to have the desired shape after sintering. This approach will provide a simple and useful tool for ceramic engineers to fabricate complicate bodies with tight dimensional tolerances.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.889-893
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• 2007

The demand of quality green banana chips is increasing in the world snacks market, therefore, the preparation of quality chips and their subsequent shelf life in packaging were evaluated in this study. Banana slices were fried in hot oil to the desired moisture content (2-3%) and oil content (40%) in chips at 3 different temperatures, and the impact of different pretreatments were compared by sensory assessment. A linear relationship between time and temperature was used to achieve the optimal processing conditions. Banana slices fried at the lower temperature of $145^{\circ}C$ took longer to reach the desired chip qualities, but gave the best results in terms of color and texture. Blanching was the most effective pre-treatment for retaining the light yellow color in finished chips. For extending the shelf life of chips, moisture proof packaging in double layer high density polyethylene was more effective than single layer low density polyethylene.

• Asian Journal of Turfgrass Science
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• v.14 no.1
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• pp.273-280
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• 2000

This study was conducted to evaluate an efficiency of plant growth regulator trinexapacethy(Primo) on the growth response of bentgrass and the change to soil water content in bentgrass green. Based on the results of the study, the following results were observed. 1. During four weeks after treatment, the visual color and turfgrass density of all the treated plots with trinexapac-ethyl(Primo) were more improved rather than without. Two treatments trinexapac-ethyl /$0.02mL\m^2$ and $0.04mL/\m^2$ were more favorable than other treatments. 2. It suggested that optimum rate to reduce the bentgrass growth and to increase the turfgrass density was the trinexapac-ethyl $0.04mL/\m^2$. 3. For six weeks after treatment, all treated plots were not significantly different (P<0.05) in turfgrass root length and root dry weitht. 4. In the treated plots with trinexapac-ethyl $0.04mL/\m^2$ for 25days in bentgrass green, soil water consumption was approximately 35% to 40% compare to the non-treated control.

• Journal of the Korean Ceramic Society
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• v.32 no.9
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• pp.1047-1055
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• 1995

Mn-Zn ferrite granules were formed by a spray-drying method of the slurry containing different kinds and concentrations of binders at various temperatures. The slurry was made by conventional ceramic processing method, that is, by mixing Fe2O3, MnO, ZnO powders (52 : 24 : 24 mol%), calcining and milling. Typical shape of the spray dried granules was spherical. The compaction behavior of these granules was dependent on the spray-drying temperature and the kind and concentration of binders. At lower pressure the granules were displaced and at higher pressure the granules were deformed and fractured to fill pores among the granules. The optimum concentration of the binder was 0.5wt%. The granules containing 0.5wt% PVA 205 were deformed and fractured well and the green density was higher than others. At higher concentrations of the binder the granules were deformed rather than fractured, therefore the green density was lowered because of the remaining unfilled pores. The decomposition temperature and the heat released were increased with increasing the concentration of the binders. The compaction response of the granules containing PVA 205 was more efficient than those containing PVA 217 and PVA 117. Green density was not dependent on the degree of hydrolysis of the binders. The compaction response of the granules spray-dried at 15$0^{\circ}C$ was most efficient.

• Journal of Environmental Science International
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• v.31 no.7
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• pp.579-592
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• 2022

Much controversy has been generated over whether the ecological restoration project in Korea is faithful to the basic approach of ecological restoration compared to projects aimed at creating parks or green spaces. This study was aimed at understanding the level of awareness of practitioners in the planting design method, which is recognized as relatively important in landscape architecture and ecological restoration. The proficiency of practitioners in planting design techniques for ecological restoration projects was investigated and analyzed in seven areas: overall planting design awareness, plant species selection method, planting tree sizes, planting density, use of native species, vegetation climatic zone, soil environment, and weed control. There was no statistically significant difference between the group who thought they were experts in the field of ecological restoration and the group who thought they were experts in the field of parks and green spaces. Moreover, there was no statistically significant difference between the degree of work performance, that is, the group whose main industry was ecological restoration, the group that performed relatively more ecological restoration work, and the group that rarely performed it. Therefore, to apply desirable ecological restoration techniques in the future and to clearly differentiate between the approach in the field of parks and green spaces, the appropriate tree size or planting density selected in the ecological restoration planting design stage must be chosen. To this end, the awareness of expert groups must be improved and related laws, systems, and guidelines must be revised.

• Journal of the Korean Ceramic Society
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• v.37 no.5
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• pp.511-515
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• 2000

The effect of Ba2+ ion dissolution with different pH and amount of PAA on microstructural changes of green and sintered bodies and its electrical properties was studied in aqueous nano-size BaTiO3 slurry system. The dissolution of Ba2+ was least at strong base, pH 10.8 and by addition of amount of 0.15 wt% PAA. The green body with the lowest of dissolution of Ba2+ at pH 10.8 and 0.15 wt% PAA had minimum values of average pore size, 40nm and shown high increase of sintered density. The compact sintered at 125$0^{\circ}C$ for 2 hr with highest Ba2+ dissolution had low density and dielectric constant due to abnormal grian growth. However, the sintered body with the lowest Ba2+ dissolution had high sintered density and then shown high dielectric constant.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.264-267
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• 2005

Soft magnetic iron powders have been coated with polyester or phenol resin. And the coated powder (soft magnetic composite) have been pressed into ring type core over the pressure of 870 MPa. Green density, magnetic flux density, permeability, core loss of the samples were measured to look at the effect of the coating materials and the amount of them. Green density is increased with the amount of coating materials and shows the maximum value, 6.5 $g/cm^3$ at 5 w/o, but decreased over it. And lowest value of the core loss is showed for the 5 w/o coated samples.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.365-368
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• 2000

We have studies on the Microstructures and densities as a function of forming pressures and the magnetic properties of the specimens with additive Bi$_2$O$_3$ that sintered at 95$0^{\circ}C$ for 4.5 hours for synthesizing optimal Ni-Cu-Zn ferrite. Green density rose generally as Forming pressure increased from 1.7 ton/cm$^2$to 2.5 ton/cm$^2$and Cold Isostatic Pressure(CIP) method was more effective than Die Pressure(DP) method to high green density. Forming pressure had no influence on apparent density but on the other hand Bi$_2$O$_3$contents were strongly dominant to appaernt density than forming pressure. Bi$_2$O$_3$liquid phases created during sintering process promoted sintering and grain growth so that apparent density, grain size and permeability increased compared to that of the specimens which were sintered with non-additive Bi$_2$O$_3$.

• KSBB Journal
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• v.28 no.6
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• pp.428-432
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• 2013

The antimicrobial properties of Light-Emitting Diode (LED) are an area of increasing interest. The aim of this study was to evaluate the bactericidal effects of blue (peak at 456 nm), green (peak at 518 nm), red (peak at 654 nm) and blue-green combined (blue 456 nm : green 558 nm = 69:31) LED irradiation to pathogenic bacteria. For this, LED equipment providing power density of $10mW/cm^2$ was installed and plates were exposed to 0.9 or $3.0mW/cm^2$ to irradiate bacteria with 3.2 to $259.2mW/cm^2$ of energy density. As a result, blue and combined LED have shown bactericidal effects on Escherichia coli KCTC 1467 and Listeria monocytogenes ATCC 19115 after irradiation of $3.0mW/cm^2$ for 2 and 4 hr, respectively. Staphylococcus aureus KCTC 1916 was inhibited at 518 nm green LED irradiation. However, red LED irradiation showed no inhibitory effect to the other tested strains. Light technology that utilizes the bactericidal properties of blue (at 456 nm) and blue-green(blue 456 nm : green 558 nm = 69:31) combined LED may have potential applications in the food industry sector.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.566-571
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• 2010

Dispersion behavior of the slurries consisted of bimodal-type AlN powders was examined in non-aqueous solvent system. Azotropic solvent system and copolymer acidic dispersant were applied to the slurries. Measurements of the sedimentation height and the viscosity of the each slurry, and the test of particle size distribution of the each powder sample were conducted as examinations for the dispersion behavior at the various dispersant contents. The bimodal-type particle size distribution was continued after addition of the dispersant and small particle portions were increased as the dispersant content increases. The density of the green sheet was also increased as the dispersant content increases and a green density of $2.114\;g/cm^3$ was obtained at the sample prepared from 2.4 wt% dispersant content. The increase of large particle portions resulted in the surface defects of the green sheets.