• Applied Microscopy
• /
• v.36 no.spc1
• /
• pp.41-46
• /
• 2006

Interfacial atomic structure (chemical structure) of a Pd/ZnO hetero junction was investigated by atomic resolution high voltage transmission electron microscopy (ARHVTEM). A misfit dislocation did not work as a stress accommodation mechanism in the ZnO(0001)/Pd (111) interface. But the periodic stress localization occurred in the ZnO($10\bar{1}0$)/(200) interface. The periodicity of the local strain coincided with that of misfit dislocation. Atomic structure image of the ARHVTEM showed that an atomic arrangement across the interface was in the order of O-Zn-Pd. It was shown that mechanical weakness of the ZnO(0001)/Pd(111) interface against cyclic heating is attributable to the absence of the periodic stress localization of the misfit dislocation.

• Ocean Systems Engineering
• /
• v.3 no.3
• /
• pp.181-201
• /
• 2013

The main objective of this work is to investigate the sloshing behavior in a baffled and unbaffled three dimensional annular-sectored water pool (i.e., tank) which is located at dome region of the primary containment. Initially two case studies were performed for validation. In these case studies, the theoretical and experimental results were compared with numerical results and good agreement was found. After the validation of present numerical procedure, an annular-sectored water pool has been taken for numerical investigation. One sector is taken for analysis from the eight sectored water pool. The free surface is captured by Volume of Fluid (VOF) technique and the fluid portion is solved by finite volume method while the structure portions are solved by finite element approach. Baffled and un-baffled cases were compared to show the reduction in wave height under excitation. The complex mechanical interaction between the fluid and pool wall deformation is simulated using a partitioned strong fluid-structure coupling.

• Journal of Radiation Protection and Research
• /
• v.34 no.2
• /
• pp.65-68
• /
• 2009

Metal-semiconductor contact is very important for the operating property of semiconductor detector. $Cd_{0.96}$ $Zn_{0.04}$ Te semiconductor crystal was grown with Bridgman method, and the crystal was cut and polished. EPMA (Electron Probe Micro Analyzer) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) analysis were done to obtain the chemical composition and impurity of the crystal. Metal contact was deposited with thermal evaporator on both sides of the crystal. Detectors with Au/CZT/Au and In/CZT/Au structure were made, and I-V curve and the energy spectrum were measured with the detectors. It could be seen that the detector with the In/CZT/Au structure has superior property than the detector with Au/CZT/Au structure when the crystal resistivity was low. However, the metal contact structure effect becomes low when the crystal resistivity was high.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.25 no.3
• /
• pp.129-135
• /
• 2021

After the manual shutdown of the Wolseong nuclear power plant due to an earthquake in Gyeongju in 2016, anxiety about the earthquake safety of nuclear power plants has become a major social issue. The shear wall structure used as a major structural element in nuclear power plants is widely used as a major structural member because of its high resistance to horizontal loads such as earthquakes. However, due to the complexity of the structure, it is challenging to predict the dynamic characteristics of the structure. In this study, a three-story shear wall structure is fabricated, and the in-structure response characteristics of the shear wall structure are evaluated through shaking table tests. The test is performed using the Gyeongju earthquake that occurred in 2016, and the response characteristics due to the domestic earthquake are evaluated.

• Journal of The Korean Association For Science Education
• /
• v.25 no.6
• /
• pp.678-688
• /
• 2005

The main objective of this study was to investigate Korean university students' understanding of the structure of the atom based on a Lakatosian view. In this study, we examined twenty-three Korean university students' understandings of atomic structure using an open-ended questionnaire. The participants were all junior students majoring in chemistry education in Korea. The characteristics of students' understanding were categorized into three philosophical stances based on the classification criteria. Assertions were constructed concerning students' written descriptions of the development of scientific knowledge with respect to atomic structure: (a) characteristics of positivist response; (b) characteristics of transitional response; (c) characteristics of Lakatosian response; and (d) tendencies in students' responses.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.584-585
• /
• 2018

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.05a
• /
• pp.303-304
• /
• 2018

• Proceedings of the Korean Vacuum Society Conference
• /
• 2000.02a
• /
• pp.149-149
• /
• 2000

Alkali and alkali-earth metal on si(001) surface has been investigated widly for both scientific and technological aspects. In particular, the Ba/Si(001) system has been studied by several groups and they reported many phases such as (2$\times$3), (2$\times$4) and c(6$\times$2) 표 LEED and AES for various temperature and coverages. But there has not been the result of the atomic structure for these phases. Recently some works about the atomic structure of Ba/Si(001) at only room temperature were presented. In this study, we investigated 3-dimensional atomic structure and growth mode of Ba layer on si(001) by coaxial impact collision ion scattering spectroscopy (CAISS) at room temperature and high temperature.

• Nuclear Engineering and Technology
• /
• v.55 no.12
• /
• pp.4307-4316
• /
• 2023

In this paper, modal effective mass for asymmetric fluid-structure interaction system is defined and equations for its calculation is derived. To establish consistency, modal effective mass in symmetric structure only system is briefly reviewed, followed by a definition of the modal effective mass in asymmetric system. The equations for calculating modal effective mass in asymmetric system are derived by utilizing the properties of left and right eigenvectors. To simplify the equations, the assumption is made that the mass matrix is only affected by the fluid. The simplified equation is then compared to the equation already used in ANSYS. Finally, the validity of the modal effective mass definition and derivation in this paper is demonstrated through a simple example.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2017.05a
• /
• pp.151-152
• /
• 2017