• Applied Microscopy
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• v.37 no.1
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• pp.23-33
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• 2007

The lacrimal gland are compound tubule-acinar glands. The main lacrimal function is the production of the aqueous layer, the thickest and major constituent of the precorneal tear film. The lacrimal gland also has an important function in the defense system of the ocular surface, forming a part of the conjunctival-associated hymphoid tissue. The ultrastructural characteristics of the lacrimal gland of the rabbit were described. The lacrimal tissues of rabbits were processed through the conventional techniques for transmission electron microscopy. The secretory portions consisted of three cell types: 1. Serous cells with electron dense secretory granules. 2. Seromucous cells containing variable moderately electron dense secretory granules with flocculent material. 3. Mucous rolls containing mucous secretory granules. The serous cells were situated at the basal portion of acini, and they contained electron dense granules of variable densities and sizes. The seromucous cells contained a few protein secretory granules and more mucous secretory granules. The mucous cells contained even fewer protein secretory granules and exclusively mucous secretory granules. The epithelium of the intralobular ducts showed secretory granules, junctional complexes, and large basolateral intercellular spaces with lateral folds. These study might be helpful in determining inter-relationships, similarities and differences among the orbital glands of various physiological or pathological conditions.

• Journal for History of Mathematics
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• v.22 no.2
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• pp.27-52
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• 2009

This article discusses the contributions of the leader Oswald Veblen, who was the president of AMS during 1923-1924. In 2006, Korea ranked 12th in SCIE publications in mathematics, more than doubling its publications in less than 10 years, a successful model for a country with relatively short history of modern mathematical research. Now there are 192 four-year universities in Korea. Some 42 of these universities have Ph.D. granting graduate programs in mathematics and/or mathematical education in Korea. Rapid growth is observed over a broad spectrum including a phenomenal performance surge in International Mathematical Olympiad. Western mathematics was first introduced in Korea in the 17th century, but real significant mathematical contributions by Korean mathematicians in modern mathematics were not much known yet to the world. Surprisingly there is no Korean mathematician who could be found in MaC Tutor History Birthplace Map. We are at the time, to have a clear vision and leadership for the 21st century. Even with the above achievement, Korean mathematical community has had obstacles in funding. Many people thinks that mathematical research can be done without funding rather unlike other science subjects, even though they agree fundamental mathematical research is very important. We found that the experience of early American mathematical community can help us to give a vision and role model for Korean mathematical community. When we read the AMS Notice article 'The Vision, Insight, and Influence of Oswald Veblen' by Steve Batterson, it answers many of our questions on the development of American mathematics in early 20th century. We would like to share the story and analyze its meaning for the development of Korean Mathematics of 21st century.

• Resources Recycling
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• v.31 no.4
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• pp.56-65
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• 2022

Copper is one of the non-ferrous metals used in the electrical/electronic manufacturing industries due to its superior properties particularly the high conductivity and less resistivity. The effluent generated from the surface finishing process of these industries contains higher copper content which gets discharged in to water bodies directly or indirectly. This causes severe environmental pollution and also results in loss of an important valuable metal. To overcome this issue, continuous R & D activities are going on across the globe in adsorption area with the purpose of finding an efficient, low cost and ecofriendly adsorbent. In view of the above, present investigation was made to compare the performance of a plant root (Datura root powder) as a bio-adsorbent to that of the synthetic one (Tulsion T-42) for copper adsorption from such effluent. Experiments were carried out in batch studies to optimize parameters such as adsorbent dose, contact time, pH, feed concentration, etc. Results of the batch experiments indicate that 0.2 g of Datura root powder and 0.1 g of Tulsion T-42 showed 95% copper adsorption from an initial feed/solution of 100 ppm Cu at pH 4 in contact time of 15 and 30 min, respectively. Adsorption data for both the adsorbents were fitted well to the Freundlich isotherm. Experimental results were also validated with the kinetic model, which showed that the adsorption of copper followed pseudo-second order rate expression for the both adsorbents. Overall result demonstrates that the bio-adsorbent tested has a potential applicability for metal recovery from the waste solutions/effluents of metal finishing units. In view of the requirements of commercial viability and minimal environmental damage there from, Datura root powder being an effective material for metal uptake, may prove to be a feasible adsorbent for copper recovery after the necessary scale-up studies.

• Clean Technology
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• v.28 no.3
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• pp.218-226
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• 2022

As a result of the recent social transformation towards a hydrogen economy and carbon-neutrality, the demands for hydrogen energy have been increasing rapidly worldwide. As such, eco-friendly hydrogen production technologies that do not produce carbon dioxide (CO₂) emissions are being focused on. Among them, ammonia (NH₃) is an economical hydrogen carrier that can easily produce hydrogen (H₂). In this study, Ru/Al₂O₃ catalyst coated onmetallic monolith for hydrogen production from ammonia was prepared by a dip-coating method using a catalyst slurry mixture composed of Ru/Al₂O₃ catalyst, inorganic binder (alumina sol) and organic binder (methyl cellulose). At the optimized 1:1:0.1 weight ratio of catalyst/inorganic binder/organic binder, the amount of catalyst coated on the metallic monolith after one cycle coating was about 61.6 g L^-1. The uniform thickness (about 42 ㎛) and crystal structure of the catalyst coated on the metallic monolith surface were confirmed through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Also, a numerical optimization regression equation for NH3 conversion according to the independent variables of reaction temperature (400-600 ℃) and gas hourly space velocity (1,000-5,000 h^-1) was calculated by response surface methodology (RSM). This model indicated a determination coefficient (R²) of 0.991 and had statistically significant predictors. This regression model could contribute to the commercial process design of hydrogen production by ammonia decomposition.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.139-153
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• 2023

This study aimed to understand the spatiotemporal variations in nitrogen content in the Gyeongan stream along the main stream and at the discharge points of the sub-basins, and to identify the origin of the nitrogen. Field surveys and laboratory analyses, including chemical compositions and isotope ratios of nitrate and boron, were performed from November 2021 to November 2022. Based on the flow duration curve (FDC) derived for the Gyeongan stream, the dry season (mid-December 2021 to mid-June 2022) and wet season (mid-June to early November 2022) were established. In the dry season, most samples had the highest total nitrogen(T-N) concentrations, specifically in January and February, and the concentrations continued to decrease until May and June. However, after the flood season from July to September, the uppermost subbasin points (Group 1: MS-0, OS-0, GS-0) where T-N concentrations continually decreased were separated from the main stream and lower sub-basin points (Group 2: MS-1~8, OS-1, GS-1) where concentrations increased. Along the main stream, the T-N concentration showed an increasing trend from the upper to the lower reaches. However, it was affected by those of the Osan-cheon and Gonjiamcheon, the tributaries that flow into the main stream, resulting in respective increases or decreases in T-N concentration in the main stream. The nitrate and boron isotope ratios indicated that the nitrogen in all samples originated from manure. Mechanisms for nitrogen inflow from manure-related sources to the stream were suggested, including (1) manure from livestock wastes and rainfall runoff, (2) inflow through the discharge of wastewater treatment plants, and (3) inflow through the groundwater discharge (baseflow) of accumulated nitrogen during agricultural activities. Ultimately, water quality management of the Gyeongan stream basin requires pollution source management at the sub-basin level, including its tributaries, from a regional context. To manage the pollution load effectively, it is necessary to separate the hydrological components of the stream discharge and establish a monitoring system to track the flow and water quality of each component.

• East European & Balkan Studies
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• v.35
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• pp.153-186
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• 2013

Literature has been special for the Polish who suffered from the numerous invasions from surrounding countries for her geographical location at the center of Europe. In the late 18th century at a time when Poland was divided and ruled by Russia, Prussia and Austria, literature played an important role in uniting Poland. During the 2nd world war in which Poland was occupied by the Soviet Union and by Germany, and during the Cold War period under socialism system(1948~1989), the Polish literature was in the front to keep unique national culture with overseas migration community at the center. The Polish Diaspora literature from 19th century up to now has naturally embodied national sufferings from foreign powers in their literary tradition linked to the problem of 'migration'. In addition, they belong to other cultural sphere, but keep their own unique identity, which is similar to Korean Diaspora literature to a great degree. This study has two stages. In the first stage, it figures out the formation and trend of the Polish Diaspora literature followed by their meaning in the history of Polish literature. In the second stage, specific texts (two dramas) are analyzed before and after system transition in 1989. * Before system transition: S. Mrożek, Emigranci (1974), * After system transition: J. Głowacki, Antygona w Nowym Yorku (1992) Mrożek and Głowacki had themselves migration experiences with high achievement and recognition in literature not only in Poland but also in the world. In their works, hardships as 'strangers' in foreign countries, emotional wandering and agony, nostalgia to lost home land and exploration of identity were described vividly. By comparing the 2 literature texts, this study attempts to trace the change of Diaspora consciousness which Polish migrants experienced in foreign countries with different political system like socialism and capitalism.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.321-327
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• 2006

In Korea, there is a growing competitive for water resources between industrial, domestic and agricultural consumer, and the environment as many other OECD countries. The demand on water use is also affecting aquatic ecosystems particularly where withdrawals are in excess of minimum environmental needs for rivers, lakes and wetland habits. OECD developed three indicators related to water use by the agriculture in above contexts : the first is a water use intensity indicator, which is expressed as the quantity or share of agricultural water use in total national water utilization; the second is a water stress indicator, which is expressed as the proportion of rivers (in length) subject to diversion or regulation for irrigation without reserving a minimum of limiting reference flow; and the third is a water use efficiency indicator designated as the technical and the economic efficiency. These indicators have different meanings in the aspect of water resource conservation and sustainable water use. So, it will be more significant that the indicators should reflect the intrinsic meanings of them. The problem is that the aspect of an overall water flow in the agro-ecosystem and recycling of water use not considered in the assessment of agricultural water use needed for calculation of these water use indicators. Namely, regional or meteorological characteristics and site-specific farming practices were not considered in the calculation of these indicators. In this paper, we tried to calculate water use indicators suggested in OECD and to modify some other indicators considering our situation because water use pattern and water cycling in Korea where paddy rice farming is dominant in the monsoon region are quite different from those of semi-arid regions. In the calculation of water use intensity, we excluded the amount of water restored through the ground from the total agricultural water use because a large amount of water supplied to the farm was discharged into the stream or the ground water. The resultant water use intensity was 22.9% in 2001. As for water stress indicator, Korea has not defined nor monitored reference levels of minimum flow rate for rivers subject to diversion of water for irrigation. So, we calculated the water stress indicator in a different way from OECD method. The water stress indicator was calculated using data on the degree of water storage in agricultural water reservoirs because 87% of water for irrigation was taken from the agricultural water reservoirs. Water use technical efficiency was calculated as the reverse of the ratio of irrigation water to a standard water requirement of the paddy rice. The efficiency in 2001 was better than in 1990 and 1998. As for the economic efficiency for water use, we think that there are a lot of things to be taken into considerations to make a useful indicator to reflect socio-economic values of agricultural products resulted from the water use. Conclusively, site-specific, regional or meteorogical characteristics as in Korea were not considered in the calculation of water use indicators by methods suggested in OECD(Volume 3, 2001). So, it is needed to develop a new indicators for the indicators to be more widely applicable in the world.

• Journal of Preventive Medicine and Public Health
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• v.35 no.2
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• pp.141-146
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• 2002

Objectives : This study was peformed in order to assess the incidence of hypertension based on two-years follow-up of a rural hypertension-free cohort in Korea. Methods : The study cohen comprised 2,580 subjects aged above 20 (1,107 men and 1,473 women) of Chung-Song County in Kyungpook Province judged to be hypertensive-free at the baseline examination in 1996. For each of two examinations in the two-year follow-up, those subjects free of hypertension were followed for the development of hypertension to the next examination one year (1997) and two years later (1998). The drop-out rate was 24.7% in men and 19.6% in women. Hypertension was defined as follows 1) above mild hypertension as a SBP above 140 mmHg or a DBP above 90 mmMg,2) above moderate hypertension as a SBP above 160 mmHg or a DBP above 100 mmHg or when the participant reported having used antihypertensive medication after beginning this survey. Results : The age-standardized incidence of above mild hypertension was 6 per 100 person years (PYS) in men and that of above moderate hypertension was 1.2. In women, the age-standardized rate for above mild hypertension was 5.7 and 1.5 for above mild and moderate hypertension, respectively. However, the rates of incidence as calculated by the risk method were 4.8% and 1.0% in men and 4.6%, 1.2% in women, respectively. In both genders, incidence was significantly associated with advancing age(p<0.01), In men, the incidences of above moderate hypertension by age group were 0.5 per 100 PYS aged 20-39, 0.7 aged 40-49, 1.7 aged 50-59, 3.6 aged 60-69, and 5.8 aged above 70(p<0.01). In women, those the incidence measured 0.6 per 100 PYS aged 20-39, 1.8 aged 40-49, 1.3 aged 50-59, 3.3 aged 60-69, and 5.6 aged above 70(p<0.01). After age 60, the incidence of hypertension increased rapidly. Conclusions : The incidence data of hypertension reported in this study may serve as a reference data for evaluating the impact of future public efforts in the primary prevention of hypertension in Korea.

• (The) Research of the performance art and culture
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• no.19
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• pp.347-378
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• 2009

Those who were from Jaeincheon and Jaein line entertainers played great roles during transition period from traditional society to modern society, and even at present the dances of them are the representative traditional dances of Korea and the matrix of Korean originality. Nevertheless, Korea dance field has given little importance to these dances, but too much importance to Gibang dance in studying traditional dances, which causes the studies on Jaein line danced to be superficial or separate. Therefore, the aims of this article are to analyze the dances of Jaein line by Han Seong-jun, who was representative for the dances, and to appraise the historical value of them. Han Seong-jun(1874-1942) was the most influential dummer and dancer of his day in Japanese colonial times, and has been recognized as one of the masters of traditional dances. He established autonomy of traditional dances by reorganizing, collecting and stage-formalizing the dances, and systemized transmitting ways for various folk dances including a Buddhist dance, which made it possiblefor those dances to be traditional dances of Korea and the bases for creative dances. The values of Jaein line dances, which were transmitted through Han, are the following: First, the dances have been designated as national or regional intangible cultural assets, and, as the representative traditional arts, we proudly show them to the world. Second, the dances, as one of the genres of Korean dances, are the subjects of younger scholars' studies. Third, the dances become one of the representative examples of revivals of traditional dances, which tend to be extinct during modernization times, and contribute to establishing national identity and subjectivity. In addition, they contribute to discovering and transmitting other traditional dances. Fourth, the dances enable many dancers to make association, that is, Association for Preservation of Traditional Dances,for the transmitting the dances, and to distribute the dances and get many dancers to transmit the dances. Furthermore, as new performance repertories, they give another pleasure to the audience. In addition to the above, as a base for expansion of Korean creative dances, Han's dances have other values such as the following: First, in searching for a new methodology for creation, he played an important role in rediscovering the foundation in the tradition, and tried to discover nationalidentity by employing the traditional dances for expression of theme. Second, he contributed to drastically dissolving the genres by expanding the gesture language from motion factors of traditional dances, which can be compared to the modern dance. Third, he tried new challenging approaches to re-create the tradition, and contributed to pursuing the simple elements of our traditional dances as traditional aesthetics. While the dances of Jaein line have such values as the above, there are also some problems around the dances, such as the confusion in the process of transmission resulted from different transmission forms and transmitters, which we must no longer leave as it is. Furthermore, it is urgent that the rest of Jaein line dances be recovered and designated as intangible cultural assets for the sound transmission of the traditional dances.