• Journal of the Korean Ceramic Society
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• v.43 no.7 s.290
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• pp.445-450
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• 2006

The preparation of AlN powder by SHS in the system of $Al-AlN-NH_4Cl$ was investigated in this study. In the preparation of AlN powder, the effect of gas pressure and the composition such as Al, AlF, and additive in mixture on the reactivity were investigated. At 60 atm of the initial inert gas pressure in reactor, the optimum composition for the preparation of pure AlN was 35 wt%Al+5 wt% $NH_4Cl+60wt%$AlN. The AlN powder synthesized in this condition was a single phase AlN with a whisker morphology.

• Journal of Korean Home Economics Education Association
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• v.7 no.1
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• pp.121-131
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• 1995

This article is the result of the investigation on the actual condition of food preparation program carried out in elementary schools. Food preparation program belongs to the subject of ‘Shilgwa(Practice)’at elementary level. Though the result shows that instructors have no big problem in teaching theoretical part of the program, it is seriously doubtful whether students can acquire any scientifically practical knowledge which is able to be got through ‘practice’Only 4% of the investigated schools have cooking rooms, and even they have only very few cooking utensils or instruments. In spite of the importance of children’s earlier initiation into food preparation program, most schools are very poorly facilitated for education the program.

• Journal of the Korean Ceramic Society
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• v.32 no.1
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• pp.57-62
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• 1995

The coating condition of reproducible anti-reflective coating film and the light transmittance characteristics of the prepared anti-reflective coating glass were investigated as a study for the preparation of single-layer anti-reflective coating glasss. In case of coating with the sol in which the solvent was substituted with the ethanol with the addition of 0.1 mol HNO3, the coated glass showed the minimum value of the refractive index of 1.464, light transmittance of 94.2% at 550nm standard wavelength which is 3.2% higher than that of the parent glass, and the reflectance in the entire wave range of visible light. The refractive index represented its minimum at the sol concentration of 1.0 mol per 100mols of water and the higher the sol concentration, the higher the refractive index, resulting in the decrease of the light transmitance. The production condition of the reproducible anti-reflective coating on glass with the maximum transmittance of 94.2% was 4cm/min of withdrawal speed, 40$0^{\circ}C$ and 1 hour of heat treatment temperature and time, resulting in the film thickness of 94nm.

• Journal of Welding and Joining
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• v.19 no.2
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• pp.191-199
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• 2001

The oxidation and recrystallization behaviors of Ni-base single crystal superalloy, CMSX-2 were investigated to determine the condition of the preparation for transient liquid phase (TLP) bonding operations. The faying surfaces of CMSX-2 were worked by the shot peening, fine cutting and mechanical polishing treatments and the degree of working of treated surfaces was evaluated by the hardness test and X-ray diffraction method CMSX-2 was heat-treated at 1,173∼1.589k for 3.6ks in vacuum of 4mPa. The mechanically polished surface was slightly oxidized after heat treatment even in the vacuum atmosphere of 4mPa. The thickness of an oxide film increased with increasing the heating temperature and the surface roughness of the faying surface. Recrystallization occurred at the surface after heat treatment at above 1,423K when the hardness was increased more than Hv600 by the shot peening treatment while the mechanically polished or fine cut surfaces didn't recrystallized. Based on these results, it was clearfied that the mechanically polishing with fine abrasive grit could be used for the preparation of faying surface of CMSX-2 before bonding operation.

• Journal of the Korean Ceramic Society
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• v.28 no.1
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• pp.46-52
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• 1991

The hydroxyapatite powders were prepared by the reaction of Ca(CH3COO)2$.$H2O and H3PO4 in aqueous solution. Effect of Ca/P mole ration and pH value on the powder characteristics were investigated. For phosphoric acid was dissociated to PO43- ion above pH 10, the preparation condition of hydroxyapatite by H3PO4 solution had this value. Dried powders were agglomerated each other. The mean agglomerate particle diameter was minimum when the condition was pH 11, Ca/P=1.75 and its specific surface area was 97㎡/g. All powders had poor crystallinity and small CO2. It prevented CaCO3 from using aspirator in preparation and maturing time. In most cases, hydroxyapatite was decomposed into ${\beta}$-TCP at more than 800$^{\circ}C$, into ${\alpha}$-TCP at 1200$^{\circ}C$. However non-decomposed hydroxyapatite was remained in Ca/P=1.85.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.5
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• pp.216-220
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• 2001

Piezoelectric ZnO thin films by Facing Targets Sputtering(FTS) method were deposited on slide glass. The Facing Targets Sputtering system can deposit thin film at plasma-free condition and change the deposition condition in wide range. The characteristics of ZnO thin films changed with power, working pressure and substrate temperature were investigated by XRD(x-ray diffractometer), alpha-step(Tencor) and SEM(Scanning Electron Microscopy) analyses. In the results, we suggest that FTS system is very suitable for the preparation of high quality ZnO thin films with good c-axis orientation.

• Journal of Sericultural and Entomological Science
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• v.55 no.2
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• pp.44-53
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• 2019

Sericin has been removed in textile industry to improve the luster and hand of silk textile. Therefore, the sericin was considered as useless material. However, recently sericin has attracted researcher's attention since unique properties of sericin including high water retention, UV protection, and wound healing effect were reported. In spite of the useful properties of sericin as biomedical and cosmetic materials, its poor mechanical properties have restricted its industrial use in biomedical and cosmetic fields. To improve the mechanical properties, various sericins were prepared by different conditions, and the effects of the preparation condition on the structure and properties of sericin were examined. In this review paper, research trend in the structure and properties of sericin prepared with different conditions were intensively introduced.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.249-264
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• 2012

The purpose of this study is to clarify the general concept and preparation process for successful aging. At the same time another object is to find out factors which were affecting influences on the preparations for the old age and analyze the relationships between the factors and preparation for old age. 280 questionnaires were distributed to over 40 years-old workers working in Banwol and Siwha industrial complex in Kyeonggi-do. Using 261 questionnaires, frequency analysis, factor analysis and multiple regression analysis, etc were executed with SPSS 18.0 to fulfill the purposes. Findings of the study are as follows. First, health condition had a positive effect on the general preparation for old age, but age, educational career, monthly income, religion and the number of children had partially positive effects. Second, job satisfaction had a positive effect on physical and economical preparation for old age, but job commitment had a positive effect on economical preparation only. Third, Age, educational career, spouse, religion, health condition and the number of children showed different effects on those preparations.

• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.369-372
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• 2005

• Journal of Family Resource Management and Policy Review
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• v.10 no.1
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• pp.33-51
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• 2006

Today, the Korean society is experiencing an increase in serious problems, such as child abuse, unmarried mothers, single mothers, which cannot be overlooked as simply trivial family matters. The increase in these problems is caused by the rapid change that has taken place within our society, which has emasculated the power of our traditional values and behavior patterns to cope with contemporary life styles. Premarital Preparation Education is starting to gain attention as a preventive measure that can overcome this serious family crisis. Although the importance of the Premarital Preparation Education program cannot be overemphasized, there are only few cases where engaged couples and unmarried men and women are exposed to this type of program and actually experience its benefits. In other words, there is an urgent need to revitalize and increase the effects of the Premarital Preparation Education Program. This research was conducted in order to find a way to revitalize and to increase the effects of the program, so that more and more people can participate and receive benefits from it. First, we have analyzed the program's contents and the current condition on how the program is actually conducted. Then we have compared real case examples of the program and analyzed the current situation and its problems.