• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.268-276
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• 2021

As wireless communication devices become more common, interests in how to control the electromagnetic waves generated from the devices are increasing. One of the most commonly used electromagnetic wave control materials is magnetic one, but due to the features that make the product heavy and thick when applied to the product, it is difficult to use them in curved electronic devices. Therefore, a polymer flexible meta electronic device has been presented to sort out the problem, which is thin and can have various curvatures. However, it requires an additional evaluation of curvature reliability. In this study, we developed a method to predict electromagnetic wave control characteristics through the resistance/length of the conductive ink line patterns of polymer flexible meta electronic devices, which is inversely proportional to the electromagnetic wave control characteristics. As the radius of curvature decreased, the resistance/length increased, and there was little variations with the duration times of curvature. We also found that both permanent and recoverable changes along with the removal of curvature were occurred when the curvature was applied, and that the cause of these changes was newly created vertical cracks in the conductive ink line pattern due to the tensile stress applied by applying curvature.

• Journal of Conservation Science
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• v.37 no.6
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• pp.723-737
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• 2021

This study analyzed the composition and structure of materials with Buddhist paper scriptures excavated from architectural sites in 'Sum Tolgoi' of the 17^th century and carried out conservation treatment base on the result of the analysis. The scriptures were covered in dust and foreign sub stances, and were so crumpled that it was impossible to identify the form. The damage, loss, and discoloration have been identified. Buddhist scriptures written in Tibetan used indigo and ink sticks on paper as a result of UV-Vis analysis, and ink sticks as black character materials from scriptures written ancient Mongolian. SEM-EDS and Micro-XRF analyses revealed that the outlines were drawn with red lines using a mix of Minium (Pb₃O₄) and Cinnabar (HgS), or Cinnabar (HgS) alone, and the contents of the scriptures were written with silver paint. Silver chloride (AgCl) and Calcium (Ca) were identified in the silver paint component of the characters, while Calcium and Orpiment (As₂S₃) were identified in the yellow lines. Concerning the paper ground, Buddhist scriptures written in ancient Mongolian were characterized by herbal plant fiber and bast fiber, and those written in Tibetan, by bast fiber. Radiocarbon dating indicates that the paper for the scriptures was produced between the 15^th and 17^th centuries. Conservation treatment of the scriptures was carried out based on the experiment on the production of pre-coated paper and how to coat that to prevent the second damage due to the deformation and fragility of the excavated paper. The scriptures were preserved and mounted, and a neutral box was made to identify the contents of the scriptures recorded on both sides after the treatment. This conservation treatment is the result of a study that applied new conservation treatment materials and methods according to the principle of conservation treatment reversibility.

• Korean Journal of Heritage: History & Science
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• v.57 no.2
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• pp.102-115
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• 2024

Painted Cultural heritage uses various materials such as paper, silk, wood, soil, and lime as a base layer to draw on using ink sticks and express lines or colors using various colorants. The importance of underdrawings is emphasized when it comes to replication and preservation, as they can reveal the original drawing. Investigations using infrared have been extensively conducted to detect underdrawings. However, there has been a paucity of research on the influence of underdrawing detection according to the base layer. In this study, the effect of the base layer materials on underdrawing detection in painted cultural heritage was confirmed using an infrared camera and hyperspectral camera (900 to 1700 nm). The study samples marked '檢' with ink below the color layer (cinnabar, orpiment, malachite, azurite, white lead, and red lead) by the base layer materials: Paper (Dakji, indigo/Dakji), silk (silk, silk/white lead), wood (celadonite/wood), soil (celadonite/soil), and lime. The difference in the effect on underdrawing detection was minimal for paper and silk, and no significant differences were found between Dakji and indigo/Dakji, or between silk and silk/white lead. However, we found that celadonite/wood, celadonite/soil, and lime have a significant impact on underdrawing detection. In particular, for wood and soil painted with celadonite, underdrawings were not detected for all six color layers. In the case of lime, it was found that all color layers except malachite had a more positive effect on underdrawing detection. The findings of this study will aid in selecting the appropriate method for underdrawing analysis in the restoration of painted cultural heritage.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.311-327
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• 1988

Vascular changes in the periodontal ligament of the rat incisors following application of experimental orthodontic forces were examined by the India ink perfusion method. 57 rats were used for this experiment. The rats were divided into experimental group (54 rats) and control group (3 rats). 54 experimental rats were divided into group I (27 rats) and group II (27 rats). The right and left upper incisors of group. I and group II rats were separated distally with forces of 20gm, 70gm respectively. The vascular changes of periodontal ligament were observed histologically by means of light microscope after 1, 2 and 3 days of tooth movement and 1,3,5,8,14, and 21 days after removal of orthodontic force. The results were as follows; 1. After one day of tooth movement, occlusion of blood vessels, hyalinization of periodontal ligament and resorption of alveolar bone adjacent to the alveolar crest on pressure side were observed. Above the tissue changes on the pressure side of group II were more severe than those of group I. Especially, septal bone of group II was separated after 2 days of tooth movement. 2. In tension zones, periodontal space was widened and periodontal fibers were orientated in the direction of puil. The blood vessels of periodontal ligament were distended. New bone deposition was seen along the inner surface of the alveolus after 2 days of tooth movement. 3. After 3 days of tooth movement, deposition of new bone was seen along the periosteal surface of alveolar bone on pressure side, progressing with increasing after removal of orthodontic force. Remodelling of the new bone was occurred 5 days after removal of orthodontic force. 4. 3 days after removal of orthodontic force, invasion of blood vessels into the marginal periodontal ligament on pressure side was observed clearly and the vessels below the epithelial attachment were increased. 5. After removal of orthodontic force, hyalinized structures disappeared concomittantly with an invasion of blood vessels from the neighboring periodontal ligament. 14 days after removal of orthodontic force, the vessels in the periodontal ligament of group I were finished the vascular rearrangement. 21 days after removal of orthodontic force, the vessels in the periodontal ligament of group II were finished the vascular rearrangement.

• Journal of Science Education
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• v.39 no.3
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• pp.376-388
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• 2015

The purpose of this study was to develop the experiment-based problem for evaluating scientific ability of elementary scientifically gifted students, and to examine its potential of application for them. The problem for evaluating scientific ability was related to the plant vascular structure of 'the structure and function of plants' unit of elementary school science, and consisted of three components such as observing and inferring, designing an experiment, and concluding. In order to apply for scientifically gifted students, scoring criteria were detailed. For the observing and inferring domain, the arrangement and structure of vascular bundles of the dicotyledon and the monocotyledon, xylem position, reason of putting plants in ink were included. Those of designing an experiment domain were method of dissecting stems of plants, and design experimental procedures, those of concluding were the prediction of experimental results, and comparison and verification with prediction and results. Finally, the scientific ability evaluation problem was applied for 22 scientifically gifted students, who had been taught in the Science Education Institute for the Gifted adjacent University, and we had found the potential of utilization for scientifically gifted students.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.823-829
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• 1993

The basic medium oil modified alkyd resin was synthesized from linseed oil fatty acid(LOFA), phthalic anhydride(PAA), trimellitic anhydride(TMA ), and trimthylol propane(TMP) by condensation polymerization at $230^{\circ}C$. TMPTA modified water-reducible alkyd resins were synthesized with TMPTA graft copolymerization onto the basic resin at $180^{\circ}C$. Acid value of the resin was controlled by the addition of TMA and N,N-Dimethylethanol amino(DMEA) was used as an neutralizing agent to prepare water-reducible alkyd. To evaluate the optimum formulation for anionic alkyd resin, water proofness and water reducibility were estimated from the acid value or TMA contents. The effect of TMPTA on the graft copoymerization of the resin was studied by measuring molecular weight, glass transition temperature(Tg), viscosity, and gel contents. The suitable balance of water proofness and water reducibility of the resin was obtained at range of 5.3~7.0wt.% of TMA contents or 40~50 of acid value of basic resin. The molecular weight, viscosity, and gel contents of water-reducible alkyd resin were increased according to the TMPTA graft copolymerization, but Tg was decreased.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.453-459
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• 2010

Introduction: Ameloblastic carcinoma is a rare malignant lesion, and may arise from either carcinoma ex-ameloblastoma or de novo carcinoma. Aberrant promoter hypermethylation of the tumor-associated genes leading to their inactivation is a common event in many cancer types. The p16/CDKN2/INK4A gene and p16 5 protein are involved directly in regulating the cell cycles. Cadherins are cell adhesion molecules that modulate the epithelial phenotype and regulate tumor invasion. The aim of this study was to evaluate the roles of p16 and E-cadherin methylation and loss of p16 and E-cadherin expression in the malignant transformation of an ameloblastoma. Materials and Methods: Eight cases of ameloblastoma, including 4 benign ameloblastomas without recurrence, 2 benign ameloblastomas with recurrence and 2 carcinoma ex-ameloblastomas, were examined. The promoter hypermethylation profile of the p16 and E-cadherin genes was studied using methylation-specific polymerase chain reaction (MSP) and immunohistochemical staining for p16 and E-cadherin expression. Results: 1) Aberrant CpG island methylation of the p16 gene was detected in 3 of the 4 benign ameloblastomas without recurrence and 1 of the 2 benign ameloblastomas with recurrence. 2) Aberrant CpG island methylation of the E-cadherin gene was found in 1 of the 4 benign ameloblastomas without recurrence. 3) A loss of p16 expression was noted in 1 of 4 benign ameloblastomas without recurrence and 1 of 2 carcinoma ex-ameloblastomas. 4) A loss of E-cadherin expression was noted in 2 of the 4 benign ameloblastomas without recurrence, 1 of the 2 benign ameloblastomas with recurrence and 2 of the 2 carcinoma ex-ameloblastomas. 5) A loss of p16 expression was observed in 1 of the 4 cases showing aberrant methylation of the p16 gene. 6) A loss of E-cadherin expression was observed in 3 benign ameloblastoma case showing aberrant methylation of the E-cadherin gene. Conclusion: These results suggest that loss of E-cadherin expression related to the other genetic pathway (not methylation) might be an adjuvant indicator predicting the malignant transformation of an ameloblastoma. However, the number of samples in this study was too small and the relationship between the treatment methods and clinical course were not defined. Therefore, further study will be needed.

• Journal of the Korean Vacuum Society
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• v.22 no.3
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• pp.156-161
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• 2013

We fabricated transparent conductive electrodes with silver (Ag) nanofibers by electrospinning process. Ag nanofibers have high aspect ratio and fused junctions which result in low sheet resistance. Electrospinning is a fast and efficient process to fabricate continuous one-dimensional (1D) nanofibers. Ag/polymer ink were prepared in polymer matrix solution by a sol-gel method. Then, Ag/polymer nanofibers precursors are heated at $200{\sim}500^{\circ}C$ in air for 2 h to eliminate partially the polymers. The topographical features of the Ag nanofibers were characterized by FE-SEM, and the electrical property was analyzed through I-V measurement system. Finally, optical property was measured using UV/VIS spectroscopy. The transparent conductive electrodes with Ag nanofibers exhibited a sheet resistance (Rs) of $250{\Omega}/sq$ at a transparency (T) of 83%. Transparent conductive films, contain the Ag nanofibers as conductive materials, have good electrical, optical, and mechanical properties. Therefore, it is expected to be useful for the application of flexible display in the future.

• Conservation Science in Museum
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• v.13
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• pp.13-22
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• 2012

The patterns for Jeogui and Pyeseul (patterns of the queen's ceremonial robe worn and a belt ornament covering knees in the front) as owned by National Museum of Korea were made in the early 20th century and both of them were colored on paper. Through a non-destructive analysis on pigments and dyes used on both the patterns, it was attempted to identify the coloring materials. As for the analysis of the coloring pigments, the XRF was used. As a result of the pigment analysis on the pattern for Jeogui, it is presumed that lead white was used for obtaining the white color, ink stick for black color, orpiment for yellow color, cinnabar and red lead for red color, copper and arsenical or a mixture of copper carbonate and orpiment for green color whereas brass seems to have been used for obtaining other colors. The pigments used for obtaining the colors of white, black, yellow and green on the pattern for Pyeseul are the same as those used on the pattern for Jeogui whereas the red pigments used on each of the two patterns are seen to be different. Although it may be difficult to identify the kinds of blue pigments that were used on the patterns for Jeogui and Pyeseul, a mixture containing lead white is presumed to be used as blue pigment. Also, as a result of the UV-Vis spectroscopic analysis performed on the blue hanji (traditional Korean paper) of the pattern for Jeogui, it was presumed to have been dyed with indigo.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.5
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• pp.22-35
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• 2018

The purpose of this study is to understand the idea of the ideal garden, pursued by Dasan, by analyzing the production process of his writing and the location of his dwelling, and the characteristics of the garden in the writings of Dasan (茶山) Jeong Yag-Yong (丁若鏞)'s "Jaehwangsangyuincheop (題黃裳幽人帖)" is concerned with his writings on an imaginary garden (意園). This paper assumed that "Jaehwangsangyuincheop" served as a blueprint for his ideal dwelling. The main research subjects are the external scenes described in the "Jaehwangsangyuincheop", and the garden elements and spatial construction that were visualized as a Korean Ink Painting (水墨畵) through the analysis of related works. The results are as follows. First, Hwang Sang was Dasan's favorite pupil, and "Jaehwangsangyuincheop" was written by Dasan while at Boeunsanbang in the winter of 1805 as an answer to a question that Hwang Sang posed about the residence of a hermit. By referring to this response, Hwang Sang established Ilsoksanbang (一粟山房) under Mt. Cheongae in Daegu-myeon, Gangjin. Secondly, the residence in "Jaehwangsangyuincheop" has mountains behind it and water in front of it (背山臨水). The residence was used as a place to combine life and leisure. It was an ideal residence that secluded the scholar(隱士). Thirdly, Dasan's ideal garden was shown as operation of natural geography in a residential location, practically using various plant materials, expanding physical boundaries of garden, pursuing synesthetic aesthetics while enjoying garden elements, and having an active experience of the taste for the arts in the extended garden. "Jaehwangsangyuincheop" depicted the life of a scholar with the taste of elegance (雅趣), who live in reclusiveness (隱逸), which was wanted by Dasan after exile. It was realized as Ilsoksanbang. "Jaehwangsangyuincheop" was interpreted as the ideal of a feasible dwelling that faithfully reflects Dasan's conceptual thoughts on the garden.