An optimum route to synthesize composite powders with homogeneous dispersion of carbon nanotubes (CNTs) was investigated. nanocomposite powders were fabricated by thermal chemical vapor deposition of gas over nanocomposite catalyst prepared by selective reduction of metal powders. The FT-Raman spectroscopy analysis revealed that the CNTs have single- and multi-walled structure. The CNTs with the diameter of 25-43 nm were homogeneously distributed in the powders, and their characteristics were strongly affected by a kind of metal catalyst and catalyst size. The experimental results show that the composite powder with required size and dispersion of CNTs can be realized by control of synthesis condition

Aligned multi-wall carbon nanotubes (MWNTs) were synthesized through the catalytic decomposition of hydrocarbons in a quartz tube reactor. In this study, we investigated the influence of gas flow rate of feedstock on the structure and growth rate of vertically aligned carbon nanotubes produced by the floating catalyst method. As the flow rate of feedstock increased, the nanotube diameter became smaller and the length became longer. Although the growth rate also increased with the raise of flow rate, the optimum flow rate of feedstock existed for the crystallinity of carbon nanotubes.

해양사고는 맡은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있다. 이러한 해양사고의 분석은 선박의 안전 운항상의 측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템다이내믹스법을 이용하여 해양사고 원인과 개선책에 대한 모델을 구축하고, 요소의 개선에 대한 효과를 분석하고자 한다. 본 연구의 수행을 위해 해양사고 원인과 개선책의 요소를 브레인스토밍법에 의해 추출하고, 인과지도상의 정량적, 정성적, 피드백루프로 변환하였다. 그리고 표준모델과 4가지 정책모델에 대해 23년간(1997-2020) 시뮬레이션을 수행하였다.

Multi-walled carbon nanotubes (CNTs) were prepared by microwave plasma chemical vapor deposition (MPCVD) using various combination of binary catalysts and methane precursor. The maximum yield (10.3 %) of CNTs was obtained using a methane-hydrogen-nitrogen mixture with volume ratio of 1:1:2 at 1000 W of microwave power. As the microwave power increased up to 1000 W, the deposition yield of CNTs raised from 4.1 % to 10. 3 %. However, the prepared CNTs at 800 W showed the more crystalline structure than those prepared at 1000 W. The prepared CNTs over different binary catalysts had various structural conformations such as aligned cylinder, bamboo, and nanofibers. The Id/Ig value of CNTs overFe-Fe/Al2O3, Co-Co/Al2O3, and Co-Cu/Al2O3 were in the range of 0.89~0.93. Among the various binary catalysts used, Fe-Co./Al2O3 showed the highest yield.

What is the most important in articles of food is hygienic safety. Because food Is the most common thing in our everyday life, however, the importance of its hygienic safety and other many problems caused by food may be easily neglected. What is more, food is can be dangerous as much as it is directly related to human life and accidents from the same cause may have different effects on the victims according to physical and environmental differences of individuals. Thus PL action for food requires more thorough prevention and measure. Korea has been enforcing 'the Product Liability Act' since the 1<SUP>1st</SUP> of July 2002. Product Liability (PL) is liability of the manufacturer or the seller of a product to compensate for the death or injury of consumers or the loss of properties caused by the defect of the product. This study surveyed consumers' response to and the effects of the enforcement of the Product Liability Act, investigated how consumers perceived the importance of food safety and the risk of defective food based on PL standards and their experience in damage by food through a questionnaire survey, and analyzed collected data through empirical analyses (reliability analysis, factorial analysis, regression analysis and ANOVA t-test) using SPSS 10.0. Based on the results of analysis, the researcher proposed strategies for coping with the Product Liability Act in the food industry

Nano sized FeAl intermetallic particles were successfully synthesized by plasma arc discharge pro-cess. The synthesized powders shouted core-shell structures with the particle size of 10-20 nm. The core was metallic FeAl and shell was composed of amorphous Because of the difference of Fe and Al vapor pressure during synthesis, the Al contents in the nanoparticles depended on the Al contents of master alloy.

Iron-carbon nanocapsules were synthesized by plasma arc discharge (PAD) process under various atmosphere of methane, argon and hydrogen gas. Characterization and surface properties were investigated by means of HRTEM, XRD, XPS and Mossbauer spectroscopy. Fe nanocapsules synthesized were composed of three phases with core/shell structures. The surface of nanocapsules was covered by the shell of graphite phase in the thickness of nm.

Monodispersed flaky silver powder was obtained by controlling the ratios of and Agin in a mixed solution of ethylene glycol and ammonia with an addition of PVP. The effects of on its morphology and size were investigated. In molar ratio was found to be an important reaction factor for the nucleation and crystal growth of Ag powder. The synthesis of flaky powder was optimized at over 6 of molar ratio increased, the size of precipitates was increased regardless of the amount of Pt. In the absence of , the morphology and size of reduced Ag powder were found to be irregular in shape in diameter. However, homogenized fine Ag powder was obtained due to heterogeneous nucleation when used as a cat-alyst, and flaky one was synthesized with the addition of Pt over of Pt/Ag.

Although the structure of carbon nanotubes is important factor characterizing its properties, it is very difficult to control the structure of carbon nanotubes (MWNTs) and to predict the range of their diameter, which is the primary factor of MWNTs' physical properties. We tried to control the diameter of MWNTsby governing the feed injection temperature of floating catalyst method. The structure of MWNTs was influenced by the phase change of ferrocene fed as the catalyst,. The carbon nanotubes were very narrow at injection temperatures close to the sublimation pt. of ferrocene, in which most MWNTs had diameters in the range of 20~30 nm. At injection temperatures between the boiling pt. and melting pt. of ferrocene, the diameters became larger and had broad distribution. However, at injection temperatures higher than the boiling pt., the diameters became narrow again and had very uniform distribution.

본 연구는 여성노인에 의한 범죄는 여성노인의 빈곤한 상황과 관련이 있을 것으로 예측하였다. 이러한 가정을 가지고 본 연구는 여성노인들의 사회경제적 상황이 법태도의 형성에 어떠한 영향을 미치는지를 살펴보고자 하였다. 빈곤에 의해 형성된 부정적인 법태도는 범죄행위를 유발할 수 있는 위험요인이될 수 있기 때문이다. 조사는 60세 이상 여성노인을 대상으로 하였는데, 계층을 고려한 층화표출(stratified sampling) 방법으로 수집된 자료 중 433부를 분석대상으로 하였다. 여성노인들의 사회경제적 요인들은 “학력”, “직업”, “용돈조달방법”, “용돈의 양”, “가구형태”, “배우자의 사망여부”이다. 한편 법태도는 “법차별성에 대한 인식”과 “법준수태도”로 구성되어 있다. 조사결과, 사회경제적 상황이 안정적인 여성노인들일수록 법적용의 차별성에 대한 태도와 법준수태도 모두 긍정적인 태도를 보이는 것으로 나타났다. 경제적으로 비교적 안정적인 여성노인들은 경제적으로 불안정한 여성노인들에 비하여 법이 차별적이지 않다고 생각하고 있으며 법에 대한 준수태도도 강한 경향을 보였다. 반면에 빈곤한 여성노인들일수록 법태도가 부정적이어서 법이 차별적으로 적용되고 있다고 생각하고, 법을 준수해야 한다는 태도도 약한 경향이 있는 것으로 나타났다. 여성노인의 범죄행위에 대한 빈곤의 효과를 탐색한 본 연구의 결과가 시사하는 바는 다음과 같다. 첫째, 범죄통제정책은 사람들의 법태도에 영향을 주는 요인이 무엇인지에 대한 이해가 바탕이 되어야 한다는 점이다. 구체적으로 여성노인에 대한 범죄통제에 있어 사회경제적으로 소외되어 있는 여성노인 계층의 규범의 형성에 특별히 관심을 가져야 할 것으로 사료된다. 둘째, 여성노인범죄를 예방하는 정책은 보호적 관점에 입각하여 접근해야 한다는 점이다. 남녀가 불평등한 사회에서 경제적인 소외로 인한 여성노인들의 빈곤은 범죄의 원인으로 작용할 수 있다. 따라서 자립능력이 없는 여성노인들의 경제적안정을 보장할 수 있도록 사회적지원을 강화하는 것을 통하여 여성노인의 빈곤문제를 해결하는 것이 여성노인에 의한 범죄예방에 중요할 것으로 보인다.