• 대한생식의학회:학술대회논문집
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• 2007.11a
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• pp.143-144
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• 2007

• Korean Journal of Crystallography
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• v.11 no.4
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• pp.195-199
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• 2000

Ceramics based on CaTiO₃-NdAlO₃ solid solutions were synthesized in order to study their dielectric microwave properties. Microstructural analysis was performed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using different analytical methods such as energy-dispersive X-ray spectroscopy (EDXS). It was observed that the heating conditions during sintering and cooling strongly affect the microstructural development of CaTiO₃-NdAlO₃-based ceramics. Various types and concentrations of structural defects were identified, for example, dislocations, twins and/or antiphase boundaries. all such defects resulted in a degradation of the dielectric microwave properties, in particular the quality factor Q. Dielectric properties of CaTiO₃-NdAlO₃-based ceramics can be improved by an appropriate thermal treatment of ceramics which results in a decrease in the concentrations of the identified microstructural defects.

• Transactions of Materials Processing
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• v.16 no.6
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• pp.467-472
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• 2007

In this study, the effects of initial texture on the twinning formation of AZ31 Mg rolled sheet was investigated. Uniaxial compression tests were carried out on samples cut along the normal direction(ND) and roiling direction(RD), respectively, of rolled AZ31 Mg alloy sheet at various temperatures (RT, 200, 250, 300, 350, $400^{\circ}C$) with the fixed strain rate($10^{-2}/s$). The results showed that deformation twining occurred actively only in the RD specimens, which promoted homogeneous deformation as compared to the ND specimens. The effect of temperature on the formation of deformation twins was also investigated, and the slip/twin transition temperature was found to be approximately $250^{\circ}C$.

• Korean Journal of Oriental Medicine
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• v.10 no.1
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• pp.15-29
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• 2004

This paper is the research on the relationship between Lee Kyujoon(李圭晙)'s Shimqi(心氣) Philosophy and medical theory of Buyang(扶陽). Lee Kyujoon is the philosopher and medical doctor in the late Chosun Dynasty. His philosophical hypothesis is that the cosmos constitutes of the only entity, Qi(氣) and Medically, human body is also made of the only one entity, or Qi. The Qi of the body comes from Shim (心:heart). So, Encouraging the Qi(扶陽) of heart is the most critical in maintaining life. He is favorably used to prescribe the medications full of the herbs boosting the ShimYang(心陽) of body. In conclusion, his Shimqi(心氣) Philosophy and Buyang(扶陽) theory is the twins of one Shimqi(心氣) monism.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.03a
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• pp.90-106
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• 1995

The "O"S' BONDING make metallic and non-metalic crystal structures and form localized superconducting orbitals , which induce electrical conduction , semi-conduction, and superconduction. The orbitals are proced by Ampere's law, Faraday's law , Meissner effect, highcritical temperature of thecopper oxide layers. abnomal trans-membrane signal in cancer cell and plastic deformations bytwins and dislocations, In the case of alloying metals, the most deterimentla cases of electrical conduction are those of solid solution and intermetalic compound . The highest case for the hardness are also those of solid solution and intermetallic compound. It explains the contributions of the "O"S' BONDING for conduction bands and plastic deformation by twins and dislocations.ns and dislocations.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.03a
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• pp.252-263
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• 1995

It is visualized that dislocations move straightly in polycrystalline structure and the trans-grain dislocation moving occur from yield point to ultimate tensile stress. Some fracturemodes in uniaxial tensile test are ilustrated in order to explain that after the ultimate point the grains deforms by twins and the rotations of grains make cracks at the grain-boundaries by the incompatibility . The luders banks. which propagates along the axis of the specimen, are twin bands whcih are formed by rearrangement of the atoms within the structure of three-dimensional crystallizing $\pi$-bondings. The fatigue limit can be found through the atom's rolling back motion during elastic deformation inthe uniaxial tensile test by the change of the gradient.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.102-105
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• 1992

Using RF plasma CVD the diamond particles and films were deposited on Si and quartz substrate from $CH_4$-$H_2$ mixed gas. The temperature of substrate was uniformly maintained by inserting matal plate between substrate and substrate holder. As a result, the deposited diamond particles were mainly twins. The deposited diamond films were identified by SEM, XRD and Raman spectroscopy.

• Coupled systems mechanics
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• v.5 no.4
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• pp.329-340
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• 2016

The trigonal shape memory alloys (SMAs) have a great potential to be utilized as the applications with special purposes, such as actuators with high operation frequency. Most studies on the trigonal microstructures typically focus on the well-known classic herringbone pattern, but many other patterns are also possible, such as non-classic herringbone, toothbrush and checkerboard patterns. In the current work, a systematic procedure is developed to find all possible laminate twin microstructures by using geometrically linear compatibility theory. The procedure is verified by SEM images with the information of crystallographic axes of unitcells obtained by EBSD, showing good agreement. Many interesting trigonal R-phase patterns are found in the specimen. Then, their incompatibility are analyzed with nonlinear compatibility theory. The relationship between such incompatibility and the likelihood of occurrence of the microstructures is revealed. The current procedure is rapid, computationally efficient and sufficiently general to allow further extension to other crystal systems and materials.

• Journal of the Korean institute of surface engineering
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• v.28 no.4
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• pp.225-235
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• 1995

To investigate the effects of pretreatment and substrate bias on the characteristics of the diamond thin films, the thin films were deposited on the p-type Si(100) wafer by MPECVD using mixtures of $H_2$, $CH_4$, and $O_2$ gases. Deposition was carried out at the substrate temperature of $900^{\circ}C$ and at the pressure of 40torr. The effect of the pretreatment on the film formation was the examined by using SiC and diamond powders as abrasive powders. Furthermore, the substrate bias effect on the formation of the diamond film was also examined. The highest nucleation density was observed for the pretreatment with 40~60$\mu\textrm{m}$ size of diamond powders and a negative bias potential(-50V). Many defects and(111) twins in the diamond films were observed.

• Journal of Korea Foundry Society
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• v.20 no.3
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• pp.188-196
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• 2000

A vacuum casting was proposed as a new fabrication method of Si wafer for solar cell substrate. It was tried to fabricate a Si plate with good properties and to reduce the production cost by direct vacuum casting. By $5{\sim}10$ cmHg of pressure difference Si plate with $50{\times}46{\times}1.5\;mm^3$ was fabricated. For the preventing of the reaction between graphite mold and Si melt, BN powder coating or BN insert were used. The Si wafer was poly crystalline with 100 ${\mu}m{\sim}1$ mm order of grain size. And there were some twins and dislocations in the grains.