• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.685-690
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• 2011

In this study, a solvothermal reaction to prepare nanocrystalline titania was carried out using $TiCl_4$ and mixed solvents of alcohol and water. The effects of the type and the composition of alcohol on the crystal structure and agglomeration of final $TiO_2$ products were investigated. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) as well as scanning electron microscopy (SEM). In the solvothermal reaction using the n-butanol solutions with different volume ratios of n-butanol/water (100/0, 75/25, 50/50, 25/75, 0/100), the extent of agglomeration of obtained rutile $TiO_2$ was found to change with the volume ratio of n-butanol/water, and the n-butanol/water ratio of 75/25 revealed the best result for the preparation of well-dispersed nanocrystalline $TiO_2$ powders. The crystal phase of $TiO_2$ prepared through the solvothermal reaction changed with the type of alcohol in solvent (alcohol/water = 75/25). $TiO_2$ products obtained with the aqueous solutions of methanol, ethanol and isopropanol have an anatase phase, while that with n-butanol has a rutile phase. The results showed that, in the solvothermal reaction using both $TiCl_4$ as a starting material and the alcohol-water mixed solvents without any other additive, the enhancement of dispersion and control of crystal structure of $TiO_2$ products can be feasible by simply varying the composition and type of alcohol in the mixed solvents.

• (The)Study of the Eastern Classic
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• no.33
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• pp.31-56
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• 2008

Jang Hyeon-gwang(張顯光, 1554-1637), whose pseudonym or courtesy name is 'Yeoheon(旅軒)', had made a thorough study on the intrinsic nature of Neo-Confucianism in a more sincere fashion, when comparing him with other Neo-Confucianists in Joseon period. Also he was a renowned scholar who expanded its philosophical system in-depth. Yeoheon thereby had strengthened his philosophical system accordant with the Great Learning(大學) and Doctrine of the Mean(中庸), which are the fundamental systems of Neo-Confucianistic education. Based on such considerations, Yeoheon's thought on education can be illuminated from three different perspectives. First, Yeoheon deepened his a theory of good governance by a virtuous ruler(聖人君主論, pronounced, 'Seongingunjuron') as the standard of education. Essentially, his theory pursues Refraining from desire, and preserving the laws of nature(存天理?人欲, pronounced, 'Joncheolliarinnyok'), and put emphasis on ethical awakening, and the governance through a virtue of moral excellence. Second, Yeoheon stressed the learning theories related to 'sincerity' or true heart(誠) and 'piety' or 'respect'(敬)) as the form of education(誠敬, pronounced, 'Seonggyeong'). Also he expounded that people needs "to establish a ground of Respect and Sincerity in their mind." He recognized the differences between the two virtues, meanwhile, however, he understood it as in an identical context. Third, Yeoheon advocated harmony between separation and integration(分合, pronounced, 'Bunhap') as a method for education. Through his unique 'Discourse on Longitude and Latitude', dubbed, 'Li-Gi Gyeongwiseol (理氣經緯說) in which the principle(Li, 理) is equal to the intrinsic energy or material force(Gi, 氣), he maintained his view on the Doctrine of the Mean, in that he was not inclined to either sides according to the logic of Change(易, pronounced 'Yeok'). When reviewing Yeoheon's contemplation in education in the meaning of modern education, he laid the standards for education on the establishment of morality, and he also provides us with an idea which induces us to look through the form and method for education from the perspective of Doctrine of the Mean. In short, Yeoheon's view on education embodies wisdom of traditional Neo-Confucianistic Education having consistency, and it provides for an implication of the review of the importance of the balance in relation to methodological bias toward confusion in the standards for modern education, and unsystematic contents therein.

• (The)Study of the Eastern Classic
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• no.41
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• pp.7-35
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• 2010

Jang Hyungang(張顯光, 1554~1570) was one of the very famous Neo-Confucianists of T'oegye School in the Chosun dynasty. Jang, nevertheless, refused to accept Toegye's theory and had developed his own theory called li-qi-gyeong-wi-seol(理氣經緯說). So the theory was very unique in the history of Korean Neo-Confucianism. He matained that Tao(道), meaning the universal process which all beings including the human must follow, is accomplished by the unity of li(理, principle) and qi(ch'i, 氣, material force). He compared li and qi to warp(經) and woof(緯). According to his explanation, Tao is fulfilled by combining li and qi, as a textile is woven the combination of warps and woofs. He could, for I know, succeed to emphasize the unity of li and qii through this theory. Lots of Scholars in the Chosun dynasty criticized Jang's theory of li and qi for regarding li and qi as one, and thought that the theory originated from Luo Ch'inshun(羅欽順, 1465~1547), a famous Neo-Confucianist of in Early Ming China. Luo Ch'inshun maintained li-qi metaphysical monism that li and qi is united entity. In this respect, it seems that Jang's theory is similar to Luo's. However, I think that there are very important differences between the two. It is true that the main characteristics of Jang's theory is the unified relations between li and qi in this world. In the system of his philosophy, nevertheless, the topological position of li and qi are different in grade each other. Jang insisted that li is a supreme being to be materialized and realized through the movement of qi'in the process of universal development. Qi is accordingly only a kind of matter which completes li. In this sense, Jang's theory can be regarded as li metaphysical monism that li is the only substance. It means that Jang Hyeongwang's theory is a great contrast to Luo Ch'inshun's li-qi metaphysical monism.

• (The)Study of the Eastern Classic
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• no.50
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• pp.179-209
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• 2013

This study takes as its text "Yangarok", the record written by Mukjae Lee Mun Geon (1494-1567) about his grandson rearing and examines the conflicts between the grandfather and the grandson. The reason it is focused on the conflicts between the grandfather and the grandson particularly among many aspects of Yangarok is that the paper notices the dual feelings of love and hatred lying in the mind of Mukjae, the subject of the narrative. Because the record of grandson rearing plainly reflects the dual elements of the grandfather, love and hatred, expectation and disappointment, and hope and resignation, it shows the acute conflicts between the two persons well. At the time of the grandson's birth, Mukjae went through a gloomy period both in family and socially. He had to taste tremendous frustration in the status as an exile pushed back from the center of the political world, and his only son was handicapped, so he could not expect his caring after that. Spending each day in such frustration, he faced the birth of his grandson just like a miracle. However, the excitedness and expectation he had in the beginning of the child raising were turned into disappointment and complaining as time went by. His change lets us think about the distance between love and hatred existing in human relations. This study analyzes Yangarok but is focused on the conflicts between the grandfather and the grandson for further discussion, so it attempts to understand Yangarok from a different perspective. First of all, Chapter 2 of this article notices the fact that cause results in effect and examines the ultimate factors raising grandfather-grandson conflicts. Next, Chapter 3 considers the concrete aspects of grandfather-grandson conflicts. Based on the above examination on the causes and aspects of the conflicts, Chapter 4 focuses on the value that Yangarok has as the material for introspection and lays the ground to think about the messages that this record implies for contemporaries.

• (The)Study of the Eastern Classic
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• no.71
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• pp.147-180
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• 2018

Seokjeong JEONG-JIK LEE is a scholar who tried to render a form of service for his country by writing works of literature during the crisis of the Period of Modern Enlightenment. He mainly expressed his perception of reality through an evaluation of historical figures. He left behind a text on the Analects of Confucius, which is known as the '10 questions and answers regarding the Analects of Confucius', in his posthumous work. It seems that he wrote it to be used as lecture material for his students. The purpose of this thesis is to analyze his recognition to the Analects of Confucius and its learning direction expressed in the writing '10 questions and answers regarding the Analects of Confucius'. With respect to the word ren(仁), which is the most fundamental concept of the Analects, he viewed his life in an introspective way from the standpoint of a 'Hoinyupe(好仁有蔽)', which means that if you like kindness and fairness but don't like learning it, then there will be negative effects, and through the 'Gwangwajiin(觀過知仁)', which means that you will know for sure kindness and fairness when you observe wrongdoing, not the general viewpoint of 'Humaneness or Love'. He tried to determine the meaning of ren, and virtue(德) through a common denominator from an overall point of view. It might have been a reflection of his thoughts that a sound comprehension of powerful countries was needed. In terms of relationship between Gunja(君子) and Myeong(命), Gunja needs to make constant efforts to understand Myeong as a talented person who can maintain order. The direction of learning was examined under three categories: Jongipjibang (從入之方), Gunjajiryu(君子之類), and Sumunihae(隨文而解). Jongipjibang is defined as a way to complement the weaknesses of leaners according to their characteristics and it promotes a focus on pushing ethics into practice rather than acquiring knowledge as it is today. Gunja was classified into 3 stages. However, it merely provides standards to help learners' understandings, so not all students may fall into these stages. Sumunihae gives explanations of commentaries on the book. Seokjeong remarked that the meaning was not different even if the same concept was annotated differently in the "Four Books". This is because the context was emphasized according to the principle of 'Sosisojeol Pilchakpilseom (所始所切, 必着必贍)'.

• Journal of Life Science
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• v.31 no.5
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• pp.511-519
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• 2021

The Perilla frutescens var. japonica HARA is widely cultivated in Korea for vegetable leaves and oil seeds. Perilla species have been used for food and medicine and are known to contain many functional compounds. In this study, we investigated the functional compound contents of Perilla during its growth stages to analyze the optimal harvest time and conditions. The contents of the Perilla sprouts were analyzed according to culture environment and days of growth. Sprouts grown in soil under natural light conditions showed high rosmarinic acid (23.19±0.16 mg/g) and GABA (0.55±0.05 mg/g) content. Therefore, the results suggest that 6 to 8 days after sowing in soil under natural light conditions was the optimum harvest condition for sprouts. Also, the functional compounds of Perilla were analyzed according to growth stage and plant part. As a result, caffeic acid and rosmarinic acid exhibited the highest content in the stage from vegetative growth to reproductive growth (0.28±0.03 ~ 0.30±0.07 mg/g rosmarinic acid and 20.60±7.02 ~ 19.37±3.18 mg/g caffeic acid), and luteolin and GABA showed the highest content in the reproductive growth stage and in the early stages of vegetative growth, respectively (31.11±2.98 ~ 22.35±1.64 ㎍/g luteolin and 0.42±0.09 ~ 0.37±0.04 mg/g GABA). It was confirmed that the content of caffeic acid (0.34±0.03 mg/g), rosmarinic acid (55.22±9.33 mg/g) and luteolin (1,044.89±6.72 ㎍/g) was the highest during the bolting stage. Overall, we identified the timing of the highest level of functional compounds in the sprouts and mature leaves of Perilla. These results suggest a suitable harvest time and conditions for sprouts and leaves for the use of Perilla as a functional material.

• Conservation Science in Museum
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• v.26
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• pp.161-182
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• 2021

A jungwangu, a type of medium-sized mortar, is a firearm with a barrel and a bowl-shaped projectileloading component. A bigyeokjincheonroe (bombshell) or a danseok (stone ball) could be used as a projectile. According to the Hwaposik eonhae (Korean Translation of the Method of Production and Use of Artillery, 1635) by Yi Seo, mortars were classified into four types according to its size: large, medium, small, or extra-small. A total of three mortars from the Joseon period have survived, including one large mortar (Treasure No. 857) and two medium versions (Treasure Nos. 858 and 859). In this study, the production method for medium mortars was investigated based on scientific analysis of the two extant medium mortars, respectively housed in the Jinju National Museum (Treasure No. 858) and the Korea Naval Academy Museum (Treasure No. 859). Since only two medium mortars remain in Korea, detailed specifications were compared between them based on precise 3D scanning information of the items, and the measurements were compared with the figures in relevant records from the period. According to the investigation, the two mortars showed only a minute difference in overall size but their weight differed by 5,507 grams. In particular, the location of the wick hole and the length of the handle were distinct. The extant medium mortars are highly similar to the specifications listed in the Hwaposik eonhae. The composition of the medium mortars was analyzed and compared with other bronze gunpowder weapons. The surface composition analysis showed that the medium mortars were made of a ternary alloy of Cu-Sn-Pb with average respective proportions of (wt%) 85.24, 10.16, and 2.98. The material composition of the medium mortars was very similar to the average composition of the small gun from the Joseon period analyzed in previous research. It also showed a similarity with that of bronze gun-metal from medieval Europe. The casting technique was investigated based on a casting defect on the surface and the CT image. Judging by the mold line on the side, it appears that they were made in a piece-mold wherein the mold was halved and using a vertical design with molten metal poured through the end of the chamber and the muzzle was at the bottom. Chaplets, an auxiliary device that fixed the mold and the core to the barrel wall, were identified, which may have been applied to maintain the uniformity of the barrel wall. While the two medium mortars (Treasure Nos. 858 and 859) are highly similar to each other in appearance, considering the difference in the arrangement of the chaplets between the two items it is likely that a different mold design was used for each item.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.9-16
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• 2022

Rice is one of the most important staple foods in Wnju, Jeonbuk, South Korea. However, rice consumption has dramatically decreased as eating habits have diversified owing to rapid economic growth. Recently, floury endosperm rice varieties have been developed to invigorate the rice processing industry, because dry-milled rice flour is economically and environmentally suitable for massive rice flour distribution. The National Institute of Crop Science has developed 'AromaT', an early-maturing black rice with floury-endosperm, suitable for tea and dry milling. 'AromaT' was derived from a cross between 'Suweon542' as the floury endosperm source and 'Heugjinju' as the black and aromatic source. In this study, 'AromaT' and its parents, 'Suweon542' and 'Heugjinju', were analyzed for agronomic traits, anthocyanin content, and their major physicochemical properties by different planting date. The field experiment was conducted in Wanju, Jeollabuk-do Province, South Korea, in 2019. The transplanting dates were May 30 (ordinary season), June 25 (double-cropping season), and July 10 (late season). The yield performance of brown rice 'AromaT' was 330 kg/10 a in the double-cropping cultivation method and was the highest among the transplanting dates. The floury endosperm of 'AromaT' was derived from 'Suweon542' containing 'flo7', located on chromosome 5 and known to control floury endosperm. With the late planting date, the anthocyanin content of 'AromaT' was 570.5 mg/100 g, much higher than that of 'Heugjinju' (376.3 mg/100 mg). The brown rice of 'AromaT' also exhibited the pop-corn-flavoring 2-acetyl-1-pyrroline, exclusively detected in aroma rice varieties. The average particle sizes of 'AromaT' and 'Suweon542' were 67.12 ㎛ and 70.9 ㎛, respectively, lower than that of 'Heugjinju' (95.5 ㎛) with a black transparent endosperm. The average damaged starch content of 'AromaT' was 8.1%, lower than that of 'Heugjinju' (10.05%) and Suweon542 (9.5%). As a result, 'AromaT' with high anthocyanin content, fine particle size, and low damaged starch content is expected to provide a new rice material in various processing fields.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.345-353
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• 2022

This study aimed to fundamentally understand changes of cell parameters of cation-exchanged mordenites using high resolution X-ray powder diffraction for studies that immobilization of various heavy metal cation using synthesis mordenite (Na_6.6Al_6.6Si_41.4O₉₆·20.4H₂O, Na-MOR). As a results of measurement by Thermogravimetric analysis (TGA), it was confirmed that 19.4, 20.4 water molecules per unit cell were present in monovalent-cation substituted MOR (Cs-MOR, Na-MOR), and 21, 23.1, 23.2 water molecules per unit cell were present in divalent-cation substituted MOR (Pb-MOR, Sr-MOR, Cd-MOR). The space group of all the samples were identified as Cmcm belonging to the orthorhombic crystal system. Compared to Na-MOR, starting material, relative peak intensity of (110) and (200) is significantly changed after cation substitution whereas peak position is almost similar. Also, (220) peak that was not found in Na-MOR was clearly observed in Pb-, Cd- and Sr-exchanged MOR. Thus, it was estimated that changes of atomic distribution usually occurred on ab-plane while changes of cell parameters were little. Detailed changes in the cell parameters of cation-exchanged mordenites were derived from whole profile fitting method using the GSAS suite program. Changes in the axial lengths and unit cell volume of cation substitution showed different relationship depending on ionic radius and charge number. In case of monovalent-cation substituted MOR, the length of a-axis increases whereas the length of b- and c-axis decrease by absorbed cation radius. In the case of divalent-cation exchanged MOR, the length of a-axis usually decreases while the length of b- and c-axis increases by cation radius. It was confirmed that unit cell volume of monovalent and divalent cation substituted MORs had an independent tendency by cation radius.

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.107-121
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• 2023

This study analyzed the polyphenol, flavonoid contents, antioxidant activity, anti-aging activity and phenol component contents of Saccharina japonica (SJ), Costaria costata (CC) extracts with hot water, 95% methanol, 95% prethanol for investigating possible utilization of SJ and CC extracts. The result revealed that the SJ and CC methanol extracts showed the highest polyphenol and flavonoid contents, 4.63 mg TAN/g, and 4.19 mg QUE/g respectively. Also, the SJ and CC methanol extracts showed higher antioxidant activity than prethanol and hot water extracts, whereas the ABTS radical scavenging activities were the highest in prethanol extracts (IC₅₀ = 15.4, 10.3 ㎍/µL). In anti-aging activity for evaluating the anti-wrinkle activity and skin whitening activity, the CC methanol extracts had high collagenase inhibitory activity (88.3%), and the SJ prethanol extracts showed higher elastase inhibitory activity (19.0%) compared to other extracts. Then the tyrosinase inhibitory activity was significantly higher in the SJ and CC methanol extracts (41.8, 30.3%, respectively), whereas prethanol extracts were the lowest. To identify the phenol component contents of SJ and CC extracts, 4-hydroxybenzoic acid, naringenin, naringin and nicotinic acid were measured using LC-MS/MS. As a result, the phenol contents were the highest in SJ methanol extract (4-hydroxybenzoic acid), SJ and CC prethanol extract (naringin and naringenin) and CC prethanol extract (nicotinic acid). Lastly, the antioxidant activity of SJ and CC showed high correlations with polyphenol and flavonoid contents (R = -0.946~0.883). These results suggest that prethanol or methanol extracts of SJ and CC have higher antioxidant activities, anti-aging activity and the potential to be used as material for health functional food and cosmetics.