• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.116-126
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• 2013

Glycol ethers are a group of solvents based on alkyl ethers of ethylene glycol commonly used in paints. These solvents typically have a higher boiling point, together with the favorable solvent properties of lower-molecular weight ethers and alcohols. The word "Glycol ethers" was registered as a United States trademark by Union Carbide Corp. Typically, glycol ethers are found in pharmaceuticals, sunscreens, cosmetics, inks, dyes and water based paints. On the other hand, glycol ethers are used in degreasers, cleaners, aerosol paints and adhesives. Most glycol ethers are relatively water soluble, biodegradable and only a few are considered toxic. Therefore, they are unlikely to pose an adverse risk to the environment. Recent study suggests that occupational exposure to glycol ethers is related to low motile sperm count in men, but the finding has been disputed by others. In this study, skin permeation of 3 types glycol ethers were studied in vitro using matrix such as solvent and detergent. The absorption of glycol ethers[methyl glycol ethers(MC), ethyl glycol ethers(EC) and butyl glycol ethers(BC)] has been measured in vitro through rat skin. Epidermal membranes were set up in Franz diffusion cells and their permeability to PBS measured to establish the integrity of the skin before the glycol ethers were applied to the epidermal surface. Absorption rates for each glycol ethers were determined and permeability assessment made to quantify any irreversible alterations in barrier function due to contact with the esters. Types of glycol ethers in vitro experimental results on MC> EC> BC quickly appeared in the following order: skin permeation was beneficial to the skin permeation small molecular weight, the difference in chemical structure, such as hydrophilic, because with the partition coefficient and solubility mechanisms and passive diffusion to increase the speed at which transmission is considered.

• The Journal of the Petrological Society of Korea
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• v.6 no.2
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• pp.77-85
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• 1997

The Early Proterozoic reworked rock association occurs within the Preacmbrian high grade metamorphic rocks in the area of Daqingshan, Inner Molgolia. In this association, the various large scale ductile deformation belts, form a nappe structure where the foliation steeply dips to north and the lineation ($340^{circ}-30^{\circ}$) plunges at $45^{\circ}55^{\circ}$. This result indicates the subduction/extension with northern part thrusting over the southern part at high angle. The southern subducted microlithon has the characteristics of prograde metamorphism. The northern thrusted microlithon shows the evidence of retrograde metamorphism with decreasing pressure and increasing temperature. The main rock types of Early Proterozoic Moyites are biotite adamellite and syenogranites occurring in the form of small batholiths or stocks and alkali-feldspar granites in veins. The biotite adamellites are progressively contacted with the Archean and Early Proterozoic rocks and contain a great deal of enclaves of metamorphosed rocks, suggesting an anatexis origin. The geochemical characteristics of moyites show the typical features of anatexis granite. At middle to late Early Proterozoic time, the continent-continent collision formed the large scale thrusting and imbrication of Archean basement rocks. According to the mineral assemblage and thermobarometer of Paria et al. (1988) give the following P-T condition : up-faulted block; $700-710^{\circ}C$, 0.72-0.78 Gpa (early stage) and $600^{\circ}C$, 0.44 Gpa (late stage), footwall block; $620^{\circ}C$, 0.8 Gpa (early stage), $620-840^{\circ}C$, 0.64-0.45 Gpa (peak) and $620-630^{\circ}C$, 0.35Gpa (late stage). These results suggest a clockwise P-T-t path (jin et al., 1991, 1994). According to the depth-temperature model in the comperature subduction zone and the experimental data of Wyllie et al. (1983), we propose a tectonic-magmatic-thermal model to account for metamorphism-anatexis of moyite occurring in subduction-shear zone.

• Journal of the Korean Vacuum Society
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• v.20 no.6
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• pp.395-402
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• 2011

The nanomechanical properties of fully lithiated and unlithiated silicon nanowire deposited on silicon substrate have been studied with atomic force microscopy. Silicon nanowires were synthesized using the vapor-liquid-solid process on stainless steel substrates using Au catalyst. Fully lithiated silicon nanowires were obtained by using the electrochemical method, followed by drop-casting on the silicon substrate. The roughness, derived from a line profile of the surface measured in contact mode atomic force microscopy, has a smaller value ($0.65{\pm}0.05$ nm) for lithiated silicon nanowire and a higher value ($1.72{\pm}0.16$ nm) for unlithiated silicon nanowire. Force spectroscopy was utilitzed to study the influence of lithiation on the tip-surface adhesion force. Lithiated silicon nanowire revealed a smaller value (~15 nN) than that of the Si nanowire substrate (~60 nN) by a factor of two, while the adhesion force of the silicon nanowire is similar to that of the silicon substrate. The elastic local spring constants obtained from the force-distance curve, also shows that the unlithiated silicon nanowire has a relatively smaller value (16.98 N/m) than lithiated silicon nanowire (66.30 N/m) due to the elastically soft amorphous structures. The frictional forces of lithiated and unlithiated silicon nanowire were obtained within the range of 0.5-4.0 Hz and 0.01-200 nN for velocity and load dependency, respectively. We explain the trend of adhesion and modulus in light of the materials properties of silicon and lithiated silicon. The results suggest a useful method for chemical identification of the lithiated region during the charging and discharging process.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.131-137
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• 2012

Polyaniline (PANI) and polypyrrole (Ppy) hollow sphere structures with controlled shell thicknesses can be easily synthesized than those of using a layer-by-layer method for cathode active material of lithium-ion batteries. Polystyrene (PS) core was synthesized by emulsion polymerization using an anion surfactant. The shell thicknesses of PANI and Ppy were controlled by amounts of aniline and pyrrole monomers. PS was removed by an organic solution. This structure increased in contact with an electrolyte and a specific capacity in lithium-ion batteries. But polymers have disadvantages such as the difficult control of molecular weights and low densities. These disadvantages were completed by controlled shell thicknesses. The amount of aniline monomer increased from 1.2, 2.4, 3.6, 4.8 to 6.0 mL, and the shell thicknesses were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, respectively. And the amount of pyrrole monomer was 0.6, 1.2, 2.4 and 3.6 mL, the shell thicknesses were 16.0, 22.0, 27.0 and 34.0 nm, respectively. In the cathode materials with controlled shell thicknesses, shell thicknesses of the PANI hollow spheres were 30.2, 42.2, and 52.4 nm, and discharge specific capacities of after 10 cycle were ~18, ~29, and ~62 mAh/g, respectively. The shell thicknesses of the Ppy hollow spheres were 16.0, 22.0, 27.0 and 34.0 nm, and discharge specific capacities of after 15 cycle were ~15, ~36, ~56, and ~77 mAh/g, respectively. Thus, shell thicknesses of PANI and Ppy increased, the specific capacities increased.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.297-305
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• 2018

Purpose: This study aimed to analyze stress distribution and maximum von Mises stress generated in intracoronal restorations and in tooth structures of mandibular molars with various types of cavity designs and materials. Materials and Methods: Three-dimensional solid models of mandible molar such as O inlay cavity with composite and gold (OR-C, OG-C), MO inlay cavity with composite and gold (MR-C, MG-C), and minimal invasive cavity on occlusal and proximal surfaces (OR-M, MR-M) were designed. To simulate masticatory force, static axial load with total force of 200 N was applied on the tooth at 10 occlusal contact points. A finite element analysis was performed to predict stress distribution generated by occlusal loading. Results: Restorations with minimal cavity design generated significantly lower values of von Mises stress (OR-M model: 26.8 MPa; MR-M model: 72.7 MPa) compared to those with conventional cavity design (341.9 MPa to 397.2 MPa). In tooth structure, magnitudes of maximum von Mises stresses were similar among models with conventional design (372.8 - 412.9 MPa) and models with minimal cavity design (361.1 - 384.4 MPa). Conclusion: Minimal invasive models generated smaller maximum von Mises stresses within restorations. Within the enamel, similar maximum von Mises stresses were observed for models with minimal cavity design and those with conventional design.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.243-280
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• 2006

At the Bujang-ri Site, Seosan, South Chungcheong Province, around 220 archaeological features, including semi-subterranean houses and pits of Bronze Age and semi-subterranean houses, pits, and burials of Baekje period had been identified and investigated. In Particular, mound burials No. 5 of 13 of Baekje mound burials yielding a gilt-bronze cap along with other valuable artifacts drew international scholarly attention. The gilt-bronze cap from the mound burial No. 5 is a significant archaeological data not only in the study of Baekje archaeology but also in the study of international affairs and exchange at that time. At the time of exposure, the gilt-bronze cap was already broken into a number of pieces and seriously damaged by corrosion, and hardening and urethane foam were necessary in the process of collecting its pieces. Ahead of main conservational treatments on cap, X-ray photograph and CT(computerizes tomography) were taken in order to examine interior structure of the cap and to decide appropriate treatments. In the five layers identified in the profile of cap, a textile layer was set between a metal and a layerof bark of paper birch for avoiding direct contact of the metal and the bark of paper birch. Analyses were executed for examining textile layer and a layer of fibroid material. According to microscopic analysis, while the textile layer consisted of the simplest plain fabric with one fold among three kinds of textile structures, the layer of fibroid material was mixed with two or three kinds of fibers. A comparative analysis with standard sample using FT-IR (Fourier Transform Infrared Spectroscopy) announced that both textiles and fabrics were hemp. Analysis of kind of the paper birch resulted in barks of paper birch with 15 fold. A metallographic microscope, SEM, and WDS were used for the analysis of microscopic structures of plated metal pieces. While amalgam plating was treated as a plating method, the thickness of the plated layer, a barometer of plating technique, was ranged from $1.72{\mu}m$ to $8.67{\mu}m$. The degree of purity of gold (Au) used in plating was 98% in average, and less than 1% of silver (Ag) was included.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.258-263
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• 2023

In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.

• Journal of Popular Narrative
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• v.25 no.1
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• pp.349-392
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• 2019

In the 1960s of Korea, the normalization of diplomatic relations between Korea and Japan led to a sense of a vigorous anxiety and fear that "Japan will once again come to the Korean peninsula". As a reaction to this, the discourse on the criticism of 'Japanese Style' strongly emerged. If the prior discourse of criticism was to express the national antipathy toward the colonial remnants that had not yet been disposed of, the critical discourse of the 1960s was the wariness of the newly created 'Japanese Style' in popular culture, and to grasp it as a symptomatic phenomenon that 'evil-minded Japan' was revealed. Thus, this new logic of criticism of the 'Japanese Style' had a qualitative difference from the existing ones. It was accompanied by a willingness to inspect and censor the 'masses' that grew up as consumers of transnational 'mass culture' that flowed and chained in the geopolitical order under the Cold War system. Therefore, the topology of 'popular things=Japanese things=consuming things' reveals the paradox of moral demands that existed within Korean society in the 1960s. This was to solidify the divisive circulation structure that caused them to avoid direct contact with the other called 'Japan', but at the same time, get as close to it as ever. It is a repetitive obsession that pushes the other to another side through the moral segregation that strictly draws a line of demarcation between oneself and the other, but on the other hand is attracted to the object and pulls it back to its side. This paper intends to listen to the different voices that have arisen in the repetitive obsession to understand the significance of the dissonance that has been repeated in the contemporary era. This will be an examination of the paradoxical object of Japan that has been repeatedly asked to build the internal control principle of Korean society, or to hide the oppressive and violent side of the power, and that can neither be accepted nor destroyed completely as part of oneself.

• Journal of Venture Innovation
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• v.4 no.3
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• pp.1-15
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• 2021

Due to long-term social distancing due to the spread of COVID-19, business trends of restaurant companies are being implemented in accordance with the changed environment such as packaging and subscription. However, even in this environment, upscale restaurants are generating high profits by trying to differentiate themselves from existing restaurants by providing high-quality services with the best facilities. Therefore, this study describes how customers' experience of upscale restaurant service influences behavioral loyalty. That is, the purpose of this study is to determine the effect of service experience on cognitive satisfaction and emotional attachment, and to examine the causal role of cognitive satisfaction and emotional attachment by confirming the relationship between these constructs and relationship commitment and behavioral loyalty. To verify this, data were collected through face-to-face interviews with 300 consumers who recently used a upscale restaurant. Of the collected data, 275 copies(91.6%) were used for the final analysis, and inaccurate or erroneous data among 25 response sheets were excluded. In this study, the validity and reliability of the data were checked and the research hypothesis was verified by using SPSS 21.0 and AMOS 20 statistical package. Frequency analysis was performed to confirm the demographic characteristics of the respondent. Structural equation model analysis(SEM) was used to confirm the fit of the research model and to verify the research hypothesis. As a result of the research hypothesis analysis, it was found that service experience had a positive effect on cognitive satisfaction, and cognitive satisfaction had a positive effect on emotional attachment, relationship commitment, and behavioral loyalty. Also, it was found that emotional attachment had a positive effect on relationship commitment and behavioral loyalty, and relationship commitment had a positive effect on behavioral loyalty. However, service experience did not affect emotional attachment. With this study, marketers and managers of upscale restaurants such as hotel restaurants need to accurately select their target audience, understand their service needs, and then present the appropriate service to them. In addition, they should not only induce cognitive satisfaction by providing excellent service to their customers, but also identify moments of truth and present appropriate services so that satisfied customers can strengthen their emotional attachment. In addition, it is necessary to strengthen the relationship with their firms by forming friendly relationships with customers who have high emotional attachment, and also to induce relationship commitment so that such customers have a strong sense of belonging and attachment to their firms.

• Sim-seong Yeon-gu
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• v.31 no.1
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• pp.1-40
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• 2016

This thesis is a study on the symbolism of 'Yeondo', a prayer for the souls in purgatory of Korean Catholic Church as a 'psychic container' for the spiritual transformation in the psyche from a perspective of analytical psychology. Yeondo' could be the 'rites of passage' of the last judgement for the souls in purgatory which is in between the heaven and the hell. And both the bereaved and the dead go through the stages of separation, transition and incorporation which are the schema of the 'rites of passage'. In particular, they have a special sense of solidarity at the stage of transition, a middle state. The symbolic process of 'Yeondo' is a spiritual transformation of recovery of paradise which could access by the confusion of death, purification and the rebirth. A spiritual reborn process of death and rebirth takes place by contacting the collective unconscious. In 'Yeondo', the death is not the end of life but the beginning of the eternal life. The confusion and disintegration caused by death can be purified and start incorporating. The rites of a paradise recovery has the meaning of trying constantly for the recovery of a wholeness. Praying for the blessing of God and a help from saints in paradise for the sake of the dead means to require conscious cooperation for the Self-realization. Integrating and recognizing unconscious also means something beyond the conscious. The blessed souls in purgatory recovers the paradise experiencing specific purifying process heading towards Self. Going into the center, abyss of unconscious will be recognized as an absolute part of oneself. One becomes the inner man, the transformed personality who is reached by the path of self-knowledge, the kingdom of heaven within oneself and can have the transpersonal energy, which enables to access to God's world and union with God. All desire and the will become one with God. In the final analysis, praying for the blessing of God and a help from saints in paradise for the sake of the dead becomes the path for the more and more conscious expansion of the alive. Therefore, 'Yeondo' as an initiation is the individuation process of the alive and the dead to reflect on themselves.