A Cu-Fe-P copper alloy was processed by accumulative roll-bonding (ARB) for ultra grain refinement and high strengthening. Two 1mm thick copper sheets, 30 mm wide and 300 mm long, were first degreased and wire-brushed for sound bonding. The sheets were then stacked on top of each other and roll-bonded by about 50% reduction rolling without lubrication at ambient temperature. The bonded sheet was then cut into two pieces of the same dimensions and the same procedure was repeated for the sheets up to eight cycles. Microstructural evolution of the copper alloy with the number of the ARB cycles was investigated by optical microscopy (OM), transmission electron microscopy(TEM), and electron back scatter diffraction(EBSD). The grain size decreased gradually with the number of ARB cycles, and was reduced to 290 nm after eight cycles. The boundaries above 60% of ultrafine grains formed exhibited high angle boundaries above 15 degrees. In addition, the average misorientation angle of ultrafine grains was 30 degrees.

중국은 자고로 禮儀의 나라라고 하며, 禮는 즉 존경하는 것, 바로 타인에 대한 공경함을 말하다. 많은 사람들은 중국어에 존경을 나타내는 말이 존재하지 않은 다고 한다. 하지만 실제 중국어에는 존경을 나타내는 많은 언어들이 있다. 뿐만 아니라 그 역사 또한 유구하다. 물론 존경을 나타내는 언어는 대화 중 경의를 나타내는 언어들을 말한다. 그중 빠질 수 없는 부분이 바로 존칭어이다. 또한 존칭어는 반드시 형성요인과 과정이 존재 한다. 본 논문은 경의를 나타내는 존칭어의 형성요인과 과정에 대해 연구하였다. 존칭어의 형성요인이 주로 신에 대한 경배에서 시작되고 국가의 형성에 따론 등급제도와 언어문자의 발전 및 유학의 흥기로 사람들 간의 관계 즉 아랫사람이 윗사람에게 존경으로 대하고, 비천한 자가 존귀한 자를 존경하며, 나이가 어린　자가 나이든 자에게 존경으로 대하는 것으로 발전하게 되었다. 또한 이런 관계에는 상대방에 대한 존경이 내재 되어야 함으로 존칭어를 사용하게 되었다. 또한 많은 존칭어들은 夏, 商, 周 및 秦, 漢대의 발전을 통해 지금까지 사용되고 있다.

Porous HAp with three-dimensional network channels was prepared in a polymer foam process using a in-situ formation. HAp/polyol with various HAp solid contents was formed with an addition of isocyanate. Under all conditions, the obtained porous HAp had pore sizes ranging 50 μm to 250 μm. The influence of the HAp content on the physical and mechanical properties of porous HAp scaffolds was investigated. As the solid content increased, the porosity of the porous HAp decreased from 79.3% to 77.9%. On the other hand, the compressive strength of the porous HAp increased from 0.7 MPa to 3.7 MPa. With a HAp solid content of 15 g, the obtained porous HAp had physical properties that were more suitable for scaffolds compared to other conditions.

The 21st Century Frontier Program, which is one of the R&D programs funded by Korean government, was launched in 1999 to elevate the status of Korean science and engineering capabilities to the advanced nation in the strategic fields. Currently, 23 different fields of science and engineering programs are carried out by researchers in institutes, universities and industries. Center for Advanced Materials Processing (CAMP) was formulated in 2001 to develop the advanced materials as well as to improve the parts manufacturing process. The main role of CAMP is proposing and forecasting the long term vision in Materials Processing Technology and also supporting the project teams for their best performance in R&D. The CAMP program consists of 5 research areas such as, Multi-layer Ceramic Electronic Parts, Powder Formed Precision Parts, 3 Dimensional Polymer Based Composites, Functional Metal Sheets, Parts Integration Technology. An introduction of R & D activities at CAMP, specially focusing on powder metallurgy, wil be presented.

Close-coupled atomizers are of great interest and controlling their performance parameters is critical for metal powder producing and spray forming industries. In this study, designed close-coupled nozzle systems were used to investigate the effect of the nozzle types and protrusion length of the melt delivery tube on the pressure formation at the melt delivery tube tip. The observed metal flow rate was not behaving as what was earlier assumed, namely that, deeper aspiration enhanced metal flow rate. Higher aspiration pressure at the tip of the melt delivery tube increases the stability of atomization process.

In a multi-action tooling system, which is usually used for the powder compaction process to fabricate the complex multilevel parts, crack formation is crucially detrimental and should be avoided. Among various process factors, tool shape is an important factor to prevent the crack formation during powder compaction process. In this work, the effects of different tool shapes were investigated through the experimental oberservation of pore distribution in real products and the finite element analysis of residual stresses. The results were interpreted based on non-uniform powder density in the compacted parts.

비대칭 폴리비닐리덴플루오라이드(PVDF) 막을 상전환법으로 제조하였다. 도포용액은 PVDF를 용매인 N-ethyl-2-pyrrolidone (NMP)와 비용매인 1,4-dioxane, diethyleneglycol dimethyl ether (DGDE), acetone, (equation omitted)-butyrolactone(GBL)의 혼합용매에 녹여서 제조한다. 여러 첨가제가 도포용액 특성, 투과특성과 막 구조에 미치는 영향을 조사하였다. 응고제인 물과 1,4-dioxane, DGDE, acetone과의 상용성이 NMP보다 낮아서 기공크기가 작아진다. 첨가제의 양을 조절하여 기공크기를 변화시켰다. 혼합용매(수계 및 비수계)가 막의 투과성능에 미치는 영향을 살펴보았다. 용액점도뿐만 아니라 표면장력도 용매 투과특성에 영향을 끼침을 알 수 있었다.

To investigate the effect of the parameters of the plasma arc discharge process on the particle formation and particle characteristics of the iron nano powder, the chamber pressure, input current and the hydrogen volume fraction in the powder synthesis atmosphere were changed. The particle size and phase structure of the synthesized iron powder were studied using the FE-SEM, FE-TEM and XRD. The synthesized iron powder particle had a core-shell structure composed of the crystalline -Fe in the core and the crystalline in the shell. The powder generation rate and particle size mainly depended on the hydrogen volume fraction in the powder synthesis atmosphere. The particle size increased simultaneously with increasing the hydrogen volume fraction from 10% to 50%, and it ranged from about 45nm to 130 nm.

목적: 이 연구의 목적은 실생활에서의 수많은 방해 요소에도 불구하고 오랜 기간 동안 운동을 지속할 수 있는 이 유를 밝히는 것이다. 방법: 먼저 연구를 위해 오랜 기간 동안 꾸준하게 운동을 지속하는 능력을 운동그릿(exercise grit)이라고 조작적 정의한 후 그 형성 과정을 살펴보고 이론화하였다. 연구참여자는 중단 없이 3년이상 운동을 지 속하고 있는 청장년층으로 여자 5명, 남자 6명, 총 11명이며 유목적 표집법에 따라 선정하였다. 연구참여자를 대상 으로 심층면담을 통해 자료를 수집하여 Strauss와 Corbin이 제시한 개방코딩, 축코딩, 선택코딩을 순서대로 적용하 여 분석하였다. 결과: 개방코딩 결과, 상위범주 20개, 하위 범주 55개, 개념 368개가 도출되었다. 이후 실시한 축코 딩에서 패러다임 모형을 도출하였다. 패러다임 모형의 내용은 다음과 같다. 인과적 조건은 운동을 만나고 경험하게 된 계기로 자각한 운동 필요성, 환경적 영향이었고, 맥락적 조건은 운동이 주는 보상으로 심리적보상, 극강의 희열 과 재미, 멋진 외모와 건강, 사교성 향상, 성실하고 규칙적인 생활 태도, 기술 습득 및 실력 향상 등으로 나타났다. 중심현상은 그릿 강화, 습관 형성으로 목표를 향한 의지, 가족, 지인의 지지, 운동을 향한 깊은 애정과 열정 등이 었고, 중재조건은 운동 걸림돌로 주변의 부정적인 시선, 일은 운동 방해꾼 등으로 나타났다. 작용/ 상호작용은 운 동을 위한 나만의 고유 전략으로 심리전략, 운동 일정 철통 사수, 유리한 환경 구축, 운동 시간 우선 확보 등이었 고, 결과는 습관 유지로 삶이 된 운동, 평생의 동반자, 정신 수양 차원의 운동 등으로 나타났다. 선택 코딩에서는 모든 범주를 추상적으로 아우르는 핵심범주로 ‘삶에 유익한 변화를 주는 반려 운동’을 추출하였고 이에 따른 이야 기 윤곽을 서술하였다. 마지막으로 이론화 모형을 제시하여 운동그릿 형성 과정을 입체적으로 설명하였다. 결론: 이 연구를 통해 패러다임 모형의 맥락적 조건인 ‘운동이 주는 보상’으로 일어나는 신체, 심리,사회적 변화가 운동 그릿을 형성하고 습관으로 정착되는 것에 대한 구체적인 논의가 이루어졌다.

Korean agricultural industry has weakened as demand for domestic agricultural products has declined due to accelerating market liberalization, aging and shrinking of rural population, and stagnating rural households’ incomes. On the other hand, as the forth industrial revolution unfolds in earnest, tremendous changes are expected, and those changes won’t be confined to certain industries but would shaken the world we know of entirely. Smart farm, which is one example of the fourth industrial revolution, is increasingly being recognized as a new growth engine for the future as smart farm and the science and technology behind it, not the size of arable land, will determine competitiveness of the agricultural industry and drive agricultural productivity and managerial efficiency. In consideration that John W. Kingdon’s Multiple Streams Framework has recently been presented as an important theoretical model in the policy field, this study analyzed problem stream, policy stream, and political stream in the process of forming the smart farm policy, and looked into what role the government played as policy entrepreneur in policy window. The smart farm policy was put on policy agenda by the government and was approved when the government announced the Smart Farm Plan together with relevant ministries at the 5th Economy-Related Ministers’ Meeting held in April 2018. This suggests that change of the government is the most critical factor in political stream, and explicitly indicates the importance of politics in formation of an agricultural policy. In addition, actual outcome of the policy and how policy alternatives that will enhance people’s understanding will support it seem to be the key to success. It also shows that it is important that policy alternatives be determined based on sufficient discussion amongst stakeholders.