• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.699-704
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• 2018

One-dimensional nanostructures have attracted increasing attention because of their unique electronic, optical, optoelectrical, and electrochemical properties on account of their large surface-to-volume ratio and quantum confinement effect. Vertically grown nanowires have a large surface-to-volume ratio. The vapor-liquid-solid (VLS) process has attracted considerable attention for its self-alignment capability during the growth of nanostructures. In this study, vertically aligned silicon oxide nano-pillars were grown on Si\$SiO_2$(300 nm)\Pt substrates using two-zone thermal chemical vapor deposition system via the VLS process. The morphology and crystallographic properties of the grown silicon oxide nano-pillars were investigated by field emission scanning electron microscopy and transmission electron microscopy. The diameter and length of the grown silicon oxide nano-pillars were found to be dependent on the catalyst films. The body of the silicon oxide nano-pillars exhibited an amorphous phase, which is consisted with Si and O. The head of the silicon oxide nano-pillars was a crystalline phase, which is consisted with Si, O, Pt, and Ti. The vertical alignment of the silicon oxide nano-pillars was attributed to the preferred crystalline orientation of the catalyst Pt/Ti alloy. The vertically aligned silicon oxide nano-pillars are expected to be applied as a functional nano-material.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.71-76
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• 2008

Purpose: A simple and efficient method to prepare nanocrystalline ZnO thin film with pure strong UV emission on soda-lime-silica glass substrates by low-temperature annealing was improved. Methods: Crystal structural, surface morphological, and optical characteristics of nanocrystalline ZnO thin films deposited on soda-lime-silica glass substrates by prefiring final annealing process at 300$^{\circ}C$ were investigated by using X-ray diffraction analysis, field emission-scanning electron microscope, scanning probe microscope, ultraviolet-visible-near infrared spectrophotometer, and photoluminescence. Results: Highly c-axis-oriented ZnO films were obtained by prefiring at 300$^{\circ}C$. A high transmittance in the visible spectra range and clear absorption edge in the ultra violet range of the film was observed. The PL spectrum of ZnO thin film with a deep near band edge emission was observed while the defect-related broad green emission was nearly quenched. Conclusions: Our work will be possibly adopted to cheaply and easily fabricate ZnO-based optoelectronic devices at low temperature, below 300$^{\circ}C$, in the future.

• Tunnel and Underground Space
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• v.8 no.3
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• pp.209-225
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• 1998

Recently, Umbrella Arch Method(UAM), one of the auxiliary techniques for tunnelling, is used to reinforce the ground and improve stability of tunnel face. Because UAM combines the advantages of a modern forepoling system with the grouting injection method, this technique has been applied in subway, road and utility tunnel sites for the last few years in Korea. Also, several research results are reported on the examination of the roles of inserted pipes and grouted materials in UAM. But, because of its empirical design and construction methodology, more qualitative and systematic design sequences are needed. Therefore, above sequences using numerical analysis are proposed and, the effects of some design parameters were studied in this research. In order to acco,mplish these objects, first, the roles of pipe and grouting materials, steel-rib and the others in ground improving mechanism of UAM are clarified. Second, the effects of design parameters are investigated through parametric studies. Design parameters are as follows; 1) ground condition, 2) overburden, 3) geometrical formulation of pipes, 4) grouting region and 5) characteristics of pipes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.20-25
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• 2020

As nanoscience and nanotechnology advance, techniques for selective pattern growth have attracted significant attention. Silica nanoparticles (NPs) are used as a promising nanomaterials for bio-labeling, bio-imaging, and bio-sensing. In this study, silica NPs were synthesized by a sol-gel process using a modified Stöber method. In addition, the selective pattern growth of silica NPs was achieved by the surface functionalization of the substrate using a micro-contact printing technique of a hydrophobic treatment. The particle size of the as-synthesized silica NPs and morphology of selective pattern growth of silica NPs were characterized by FE-SEM. The contact angle by surface functionalization of the substrate was investigated using a contact angle analyzer. As a result, silica NPs were not observed on the hydrophobic surface of the OTS solution treatment, which was coated by spin coating. In contrast, the silica NPs were well coated on the hydrophilic surface after the KOH solution treatment. FE-SEM confirmed the selective pattern growth of silica NPs on a hydrophilic surface, which was functionalized using the micro-contact printing technique. If the characteristics of the selective pattern growth of silica NPs can be applied to dye-doped silica NPs, they will find applications in the bio imaging, and bio sensing fields.

• Conservation Science in Museum
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• v.25
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• pp.63-84
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• 2021

In order to investigate the diverse physicochemical changes that occurred in traditional Korean pottery during its production, including before and after firing, this study produced six replicas of a celadon maebyeong inlaid with cloud-and-crane designs, respectively corresponding to the process of shaping, carving, inlaying designs, first firing, glazing and second firing, respectively. It then conducted a scientific study of these six replicas and analyzed their images through high-resolution three-dimensional transmission imaging. The materials used for the replicas show different mineral phases and even colors depending on the components of each material. For example, black inlay with a high content of iron oxide (Fe₂O₃) shows dark colors and white inlay with a high alumina (Al₂O₃) content appears white. Physicochemical properties such as chromaticity and magnetic susceptibility and major components of the replicas were confirmed by the differences in the density in the computed tomography (CT) images. The characteristics of fired products such as fine structure, absorption ratio, apparent porosity, and other characteristics of the major mineral components were identified by the presence of pores and the formation of cracks inside the replicas in the image analysis.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.4
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• pp.209-218
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• 2021

Studies of pore structure in shale gas reservoirs are essential to increase recovery rates, which is in the spotlight concerning unconventional resources. In this study, the distribution of pores in shale gas reservoir sample were observed using Scanning Electron Microscope Particle Analysis (SELPA), which is appropriate to analyze the distribution of particle or shape for sample in large area. A sample from the A-068 borehole drilled in the Liard Basin was analyzed; calcite is the main mineral. The pore size ranges from tens of nanometers to hundreds of micrometers and the contribution of each pore size to overall sample porosity was determined using SELPA. The distribution of pores was determined by observing the surface in the same area at magnifications of ×1000, ×3000 and ×5000. Pores less than 100 nm were observed at high magnifications and confirm that small-scale pore distribution can be analyzed and identified rapidly using SELPA. The method introduced in this study will be useful to understand pore structures in unconventional reservoirs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1222-1230
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• 2022

The rotor blade is an important component of a tidal stream turbine and is affected by a large thrust force and load due to the high density of seawater. Therefore, the performance must be secured through the geometrical and structural design of the blade and the blade structural safety to which the composite material is applied. In this study, a 1 MW class large turbine blade was designed using the blade element momentum (BEM) theory. GFRP is a fiber-reinforced plastic used for turbine blade materials. A sandwich structure was applied with CFRP to lay-up the blade cross-section. In addition, to evaluate structural safety according to flow variations, static load analysis within the linear elasticity range was performed using the fluid-structure interactive (FSI) method. Structural safety was evaluated by analyzing tip deflection, strain, and failure index of the blade due to bending moment. As a result, Model-B was able to reduce blade tip deflection and weight. In addition, safety could be secured by indicating that the failure index, inverse reserve factor (IRF), was 1 or less in all load ranges excluding 3.0*Vr of Model-A. In the future, structural safety will be evaluated by applying various failure theories and redesigning the laminated pattern as well as the change of blade material.

• Sim-seong Yeon-gu
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• v.27 no.1_2
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• pp.28-70
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• 2012

In Jungian psychology, creation myths regard as the story of unconscious and preconscious processes(projection of archaic identity) which describe not necessary the origin of our cosmos, but the origin of man's conscious awareness of the world. Therefore projections have nothing to do with matter itself but experience of one's own unconscious. Jung emphasizes importance to understand projection in individual's conscious experience rather than in philosophical doctrine. The purpose of this thesis is to explore unconscious process of creation myths with egg symbolism in clinical cases to present universal feature of Cosmic/alchemical egg. Psychologically, creation myths retold when human mind needs new order. Depending on the attitude of ego, it can be sudden expansion of consciousness or contamination of ego by unconscious. In this study, 'chaos(messa confusa)' in creation myths as archaic identity, experience of uroboros or infant, and nigredo state in alchemy. 'Separation of primordial parents' as beginning of consciousness refers to separatio operation in alchemical process. 'Light' as attainment of consciousness. Discussion of psychological meaning of egg starts with amplification which include the concept of cosmic/alchemical/philosophical egg. Egg symbolism in this study refers to emergence of egg, tapas/brooding of egg, and separation of egg. Emergence of egg as a state of preconscious totality, psychic wholeness conceived as the thing which came before the rise of ego consciousness. Discussion of conceptssuch as Shiva bindu, hiranyagharba, germ of gold, Tathāgatagarbha follows. 'Tapas/brooding of egg' as concentration of all psychic energy into one point for self reflection. Discussion includes The I Ching Hexagram 61, image of brooding egg identified with inner truth, Wonhyo's concept of jikwansasang, and Gnostic idea of Ennoia, introverted act of thinking, as well as the concept of 'Night Sea Journey'. 'Separation or hatching of egg' regarded as the idea of sudden illumination, Phanes, the shining God, and "sun-point," in alchemy. Birth of fledgling as birth of new personality. As a conclusion, psychological meaning of cosmic egg/creation myths is the story of separating from 'Not-I'(unconscious, object, undifferentiated) to 'I'(ego, subject, differentiated) which shares the same meaning as individuation process.

• Cartoon and Animation Studies
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• s.50
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• pp.299-325
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• 2018

Humans have made a third person over a long history and differentiated them from each other. Discrimination of 'us' and 'them' has led Derrida to make works to look upon the human nature towards animal strangers. This study tries to examine upon the expansion of animal strangers by focusing on 'The Animal That Therefore I am.' Furthermore, the research asserts to pay more attention to animal strangers by looking at his works of how modern people think about animals in the current society. Derrida expresses his 'humiliation' that he felt when he faced his cat after a shower. This emotion brings up the topic that was neglected in the conventional wisdom and casts doubts on this. This emotion of humuliation is only felt by humans, and he explains this is one way of feeling like a 'human.' The researcher therefore focuses on the 'experiences of humans' and looks at the ambivalence of humans in culture and the irony in natural animals. This perspective criticizes Speciesism, which considers people other than oneself able to be suffered. This view also tried to escape anthro-pocentrism and looked at the animals on their own. This study examines current animal strangers with theories of Donna Haraway and Jane Goodal, and analyzes Derrida's artworks with Susan Sontag's philosophy. This aims to lead to a conclusion of how to reach an optimal relationship between human and animal. By focusing on Derrida, who has not been highlighted yet in this country, hopes to create effective communication between human and animal by explaining his artworks through new philosophy of animals.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.6-13
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• 2010

In this study, Ga-doped ZnO (GZO) thin films have been fabricated on Eagle 2000 glass substrates at various substrate temperatures $100{\sim}400^{\circ}C$ and thin film thickness by RF magnetron sputtering in order to investigate the structural, electrical, and optical properties of the GZO thin films. It is observed that all the thin films exhibit c-axis orientation and a (002) diffraction peak only. The GZO thin films, which were deposited at $T=300^{\circ}C$ and 400 nm, shows the highest (002) orientation, and the full width at half maximum (FWHM) of the (002) diffraction peak is $0.4^{\circ}$. AFM analysis shows that the formation of relatively smooth thin films are obtained. The lowest resistivity ($8.01{\times}10^{-4}\;{\Omega}cm$) and the highest carrier concentration ($3.59{\times}10^{20}\;cm^{-3}$) are obtained in the GZO thin films deposited at $T=300^{\circ}C$ and 400 nm. The optical transmittance in the visible region is approximately 80 %, regardless of process conditions. The optical band-gap shows the slight blue-shift with increase in doping which can be explained by the Burstein-Moss effect.