• 한국세라믹학회지
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• 제43권11호
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• pp.728-733
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• 2006

The equilibrium or growth shape of ceramic materials is classified largely into two categories according to the thermodynamic conditions imposed. One is a polyhedral shape where the surface free energy is anisotropic, and the other a spherical shape where the surface free energy is isotropic. In the case of grains with a polyhedral shape of anisotropic surface free energy, socalled abnormal grain growth usually takes place due to a significant energy barrier for a growth unit to be attached to the crystal surface. In the case of grains with a spherical shape of isotropic surface free energy, however, normal grain growth with a uniform size distribution takes place. In this contribution, the state-of-the-art of our current understanding of the relationship between the crystal shape and the microstructure evolution during the sintering of ceramic materials in the presence of a liquid phase was discussed.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3478-3487
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• 2022

In this study, we incorporate an anisotropic scattering scheme involving spherical harmonics into the method of characteristics (MOC). The neutron transport solution in a light water reactor can be significantly improved because of the impact of an anisotropic scattering source with the MOC flat source approximation. Several problems are selected to verify the proposed scheme and investigate its effects and accuracy. The MOC anisotropic scattering source is based on the expansion of spherical harmonics with Legendre polynomial functions. The angular flux, scattering source, and cross section are expanded in terms of the surface spherical harmonics. Later, the polynomial is expanded to achieve the odd and even parity of the source components. Ultimately, the MOC angular and scalar fluxes are calculated from a combination of two sources. This paper presents various numerical examples that represent the hot and cold conditions of a reactor core with boron concentration, burnable absorbers, and control rod materials, with and without a reflector or baffle. Moreover, a small critical core problem is considered which involves significant neutron leakage at room temperature. We demonstrate that an anisotropic scattering source significantly improves solution accuracy for the small core high-leakage problem, as well as for practical large core analyses.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2008년도 추계학술발표대회 및 제15회 신소재 심포지엄
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• pp.5.2-5.2
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• 2008

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.280.1-280.1
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• 2007

• 한국재료학회:학술대회논문집
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• 한국재료학회 1994년도 추계 학술발표 강연 및 논문 개요집
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• pp.151-151
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• 1994

• 한국재료학회:학술대회논문집
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• 한국재료학회 1999년도 추계학술발표강연 및 논문개요집
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• pp.106-106
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• 1999

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 추계학술발표회
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• pp.101-101
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• 1997

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 춘계학술발표회
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• pp.26-26
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• 1997

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 추계학술발표강연 및 논문개요집
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• pp.81-81
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• 1998

• 마이크로전자및패키징학회지
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• 제17권4호
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• pp.41-48
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• 2010

본 연구에서는 일액형 이방 도전성 페이스트(anisotropic conductive paste, ACP) 혼합 조성의 상온 보관성을 향상시키기 위해 2-methyl imidazole 경화 촉매제를 5종의 각기 다른 물질로써 encapsulation하였다. Encapsulation용 분말 물질들은 DSC를 통해 그 융점을 관찰하였으며, 이를 통해 encapsulation용 분말 물질들을 액상으로 용융시켜 encapsulation하는 공정이 가능함을 확인할 수 있었다. Encapsulation된 2-methyl imidazole 분말을 포함한 ACP 혼합물질의 상온 보관성을 평가하기 위하여 시간에 따른 점도 변화가 관찰되었다. 그 결과, stearic acid와 carnauba wax로 encapsulation된 2-methyl imidazole 분말을 포함한 혼합물질에서 향상된 상온 보관성을 관찰할 수 있었으며, 이러한 formulation은 기본 혼합물질과도 유사한 경화 거동을 보임을 확인할 수 있었다. 최종적으로 stearic acid와 carnauba wax로 encapsulation된 2-methyl imidazole 분말을 포함한 혼합물질을 사용하여 RFID 칩을 제조된 안테나 패턴이 형성된 PET 기판에 고속 플립칩 본딩을 실시하였다. 이 경우 측정된 접합 강도는 기본 혼합물질에 비해 약 37%의 수준인 것으로 측정되었다.