• 한국자동차공학회논문집
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• 제16권6호
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• pp.58-64
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• 2008

An aluminum radius rod using rheo-forging method has been developed for heavy commercial vehicles to decrease vehicle unsprung weight. To design the shape of the rod, structural simulations are performed using two load cases. To evaluate durability performance of the rods, a test system which has simultaneous 3 axes actuating system is developed. And 3 axes durability test conditions are established based on vehicle field tests. Using the test systems and the conditions, the durability test is carried out and the rods have passed the test conditions of 700,000 cycles. The weight of a developed aluminum radius rod is 4.2kg and it was drastically reduced by 48.8 percent in comparison with the weight of a steel radius rod.

• 한국환경복원기술학회지
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• 제21권1호
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• pp.133-143
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• 2018

In spite of the growing importance of landscaping trees, the rate of flawed and withered trees damaged by pest, disease, drought or frost is increasing. In order to evaluate the performance of the Tree Protective Pad, which are developed to reduce the failure ratio in landscape planting, the tree protective pad for 'digging', 'pest controlling', and 'insulating' are tested based on the five functional criteria; moisturizing effect, wither preventive effect, pest and disease control, thermal effect, tensile strength, and environmental performance. The result of this study is as follows. The moisturizing effect of the tree protective pad for digging is found to be outstanding. According to the result of testing the pad on trees, in particular, it is better than jute tape in wither preventive effect, which means it is expected to prevent flaw and wilt from planting during the improper seasons like summertime. The experiment of installing the protective tree pad for pest controlling to the trunk of Quercus mongolica shows that preventive effect of the pad from diseases and insects is superior, and it also has economical effect by reducing the use of agricultural chemicals. The comparative test of the pad for insulating and jute tape proves that the temperature of the pad is about $2^{\circ}C$ higher than outside. The rate of tensile strength and biodegradation of the pad exceeds the optimal level, so it is revealed that the pad may be the work efficient and environment-friendly product. Likewise, by timely irrigating trees, the tree protective pad economically prevents trees from pest, disease,drought or frost, which may be caused by improper seasonal or delayed planting. As a means of reducing the flaw and facilitating the growth of trees, the exceptional performance of the pad is expected to effectively used in landscape planting and management.

• 한국결정성장학회지
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• 제11권6호
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• pp.290-296
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• 2001

균질한 형상, 좁은 입도분포 그리고 순도가 높은 미립 금속분말은 첨단산업분야에서 응용분야가 점차 확대되고 있다. 본 연구에서는 Polyol법을 이용한 마이크론 크기의 단분산 코발트 분말을 합성하였다 Polyol이 환원제 역할을 하였다. 반응온도, 반응시간, 분산제첨가 및 전구체의 농도 등을 변화시켜 코발트의 입자 크기, 형상 그리고 응집현상을 제어하고자 하였다. 최적의 합성조건은 E.G/DiE/G 부피비 1:4,$Co(OH)<_{2}$polyol 몰비 0.08~0.32 반응온도 $210^{\circ}C$, PVP/Co$(OH)_2$ 몰비 0.4이었다.