• Journal of Conservation Science
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• v.33 no.6
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• pp.399-416
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• 2017

The 'Wat Phou and Associated Ancient Settlements within the Champasak Cultural Landscape' of Laos was designated as a UNESCO World Cultural Heritage in 2001. The uppermost structure of the Sanctuary in Wat Phou has been destroyed and being variably damaged, maintenance is required through scientific and systematic diagnosis. The Sanctuary of Wat Phou was constructed mainly using sandstones and bricks. There are physical damages including fracture, break out, exfoliation and interval as well as biological damages by lichen, mosses and weeds. According to the ultrasonic velocity measurement and property evaluation of the sandstones of the Sanctuary in Wat Phou, weathering index of the eastern side sandstones is 0.10 to 0.74 (mean 0.36), showing MW grade. Southern and northern side sandstones have relatively higher properties with average weathering indices of 0.30 and 0.32. The results of slope analysis of the Sanctuary, indicated that the 4th spot in the southern side has the largest slope of $5^{\circ}W$, seemingly due to the unstable ground around the Sanctuary. Based on the relative level measurement and past drawings, the Sanctuary is verified to have been located on ground with a certain slope rather than flatland. The ground of the southern side is inclined $1.51^{\circ}$ more than that of the northern side, which will affect the structural stability of the temple. The interval width of the selected southern spot is the largest with an average width of 159.5 mm, and the largest width is 328.3 mm at the top, since the width increases above rather than below, seemingly due to the unequal subsidence of the ground. Constant maintenance for conservation is required for the structural stability of the Sanctuary in Wat Phou, which was partly collapsed and has also suffered physical damage.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.3
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• pp.137-144
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• 2002

To obtain the basic information about pedo-genetic properties and origin of the parent materials of "Yongil" series in Korea, this study was conducted. The soil characteristics such as chemical and sand particles of typifying pedon, and distributional patterns in the area were analysed. The typifying pedon of "Yongil" series was distributed on the top of rolling area in the eastern coastal area of Korea, Yonggan-ri, Heunghae-eup, Pohang-si, Gyongbuk province. The results are as follows; The "Yongil" series in Korea was distributed on the rolling hill under altituede of 50m, and was used for cultivated upland, and the total acreage about 376ha. The content of sand was more than 50%, however the clay content in the depth of 40~100cm of the soil profile rapidly increased. The medium sand (0.5~0.1mm in size) are dominant among sand fraction, but coarse one are rare. So the rate of medium to total sand was higher in IIB horizon as 0.62~0.76 than A and C horizons. The content of heavy minerals in medium sand was low as 1.0~6.6% and the ratio of quartz to feldspars was higher in Ap2 and B1 horizon as 1.7 than IIB horizon which had less than 1.39. The cumulative curves of sand particles in Yeongil series showed the well sorted and differ from residuum soils derived from sand stone, but similar to dune soils(Haeri series). So it could be deducted from this study that "Yeongil" series are aeolian deposits derived from aeolian materials and have bisequum profile; the upper part depth of 40cm was recent cover sand, the horizon of 40~100cm depth was developed in Pleistocene epoch from the same materials.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.528-547
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• 2001

The blastoporphyritic granite gneiss (BPGN) including much alkali-feldspar megacrysts occurs in Jiri mountains area, southwestern part of Sobaegsan massif, Korea. The BPGN is formed gneiss complexes with other gneisses in Precambrian. The BPGN was named as porphyroblastic gneiss with porphyroblasts of alkali-feldspar megacrysts by other researchers, but the BPGN includes of euhedral alkali-feldspars (microcline), and the boundary with the granitic gneiss represents sharp contact as intrusive relationship. The BPGN mainly composes of alkali-feldspar megacrysts, quartz, plagioclase, K-feldspar and biotite some almandine and accessary minerals are muscovite, chlorite, apatite, zircon and opaques. The alkali-feldspar is microcline with perthitic texture. An content of plagioclases show 30 to 40. Biotites occur two type, one is Brown biotite which shows compositional ranges of Mg/Fe+Mg ratios from 0.38 to 0.52, the other is Green Bt. which is retrograde product. Camels to be various sizes and shapes have composition of almandine with 73 to 80 mole percent, but represent retrogressive zoning from core (X$_{pyr}$: 15.9${\sim}$20.8) to rim (X$_{pyr}$:13.7${\sim}$15.9) to be evidence of retrograde metamorphism. Megacrysts of alkali-feldspar in the BPGN show rectangular shape of euhedral and some become ellipsoidal or spheroidal in shape and the average size up to 20 cm long. The megacryst includes of biotite, plagioclase and quartz, and rarely euhedral apatite as inclusions. In petrochemistry the BPGN represents granodiorite composition, characteristics of peraluminous S-type granitoid and calc-alkaline features.

• Journal of dental hygiene science
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• v.17 no.4
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• pp.368-374
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• 2017

The purpose of this study was to evaluate community dental hygiene practice education, by verifying its effect after applying project-based learning in improving the practical and social skills of learners. A 15-week project-based community dental hygiene practice course was held for 27 senior students, who took community dental hygiene practice course in the Department of Dental Hygiene, Gangneung-Wonju National University. Twenty-seven students were composed of 4 teams. Each team selected a target group for four workplaces for adult workers to apply the oral health promotion project. The project was then planned and conducted based on a survey on the health problems confronting each group, and an evaluation was carried out after 4 weeks. From the results obtained in comparing confidence in problem solving ability, project value, teamwork competency, and community dental hygienist competence before and after course, the improvement in project value and teamwork competence scores was not statistically significant, but all four areas showed positive results. After analyzing the project actuality, learning outcomes, and project satisfaction after course results, the actuality of the project was 19.30 points, the learning achievement was 45.19 points, and the satisfaction was 19.19 points, demonstrating that the aim of achieving actual performance competence and a learning performance exceeding expectations was accomplished. After conducting an interview survey with 8 students, it was found that they had learned social skills involving problem-solving abilities and confidence, and teamwork competence such as cooperation, role responsibility, creative thinking ability, and communication skills. Community dental hygienists should be able to acquire learner-level practical skills and social skills in the community dental hygiene and practical courses, according to their competencies and job needs. It is necessary to develop a project?based systematic learning module to enable the community dental hygiene practice to operate as a subject closely related to fields in other dental hygiene departments.

• The Journal of the Petrological Society of Korea
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• v.6 no.3
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• pp.185-209
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• 1997

Granitic rocks in the Cheongsan area cosist of three plutons-Baegrog granodiorite, Cheongsan porphyritic granite, and two mica granite. Amphilboles from the Baegrog granodiorite belong to the calcic amphilbole group and show compositional variations from magnesio-hornblende in the core to actinolitic hornblende in the rim. Biotites from the three granites represent intermediate compositions between phlogopite and annite. Muscovites from the two mica granite are considered to be primary muscovite in terms of the occurrence and mineral chemistry. Each granitic rock reveals systematic variation of major oxide contents with $SiO_2$. Major oxide variation trends of the Baegrog granodiorite are fairly different from those of Cheongsan porphyritic granite and two mica granite. The latter two granitic rocks are also different with each other in variation trends for some oxides. Thus three granitic rocks in the Cheongsan area were solidifield from the independent magmas of chemically different, heterogeneous origin. The granitic rocks in the area show calc-alkaline nature. The whole rock geochemistry shows that the Baegrog granodiorite and Cheongsan porphyritic granite belong to metaluminous, I-type granite, whereas the two mica granite to peraluminous, I/S-type granite. The opaque mineral contents and magnetic susceptibility represent that the granitic rocks in the area are ilmenite-series granite, indicating that each magma was solidified under relatively reducing environment. The tectonic environment of the granitic activity in the area seems to have been active continental margin. Alkali feldspar megacryst in the Cheongsan porphyritic granite is considered to be magmatic, judging from the crystal size, shape, arrangement, and distribution pattern of inclusions. The petro-graphical characteristics of the Cheongsan porphyritic granite can be explained by two stage crystallization. Under the smaller degree of undercooling the alkali feldspar megacrysts rapidly grew owing to slow rate of nucleation and fast growth rate. At the larger degree of undercooling the nucleation rate and density drastically increased and the small crystals of the matrix were formed.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.547-561
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• 2005

General characteristics of groundwater contamination by As were reviewed with several recent researches, and its occurrence in groundwater of Korea was investigated based on a ffw previous studies and a groundwater quality survey in Nonsan and Geumsan areas. In Bangladesh, which has been known as the most serious arsenic calamity country, about $28\%$ of the shallow groundwaters exceeded the Bangladesh drinking water standard, $50{\mu}g/L$, and it was estimated that about 28 million people were exposed to concentrations greater than the standard. Groundwater was characterized by circum-neutral pH with a moderate to strong reducing conditions. Low concentrations of $SO_4^{2-}$ and $NO_3^-$, and high contents of dissolved organic carbon (DOC) and $NH_4^+$ were typical chemical characteristics. Total As concentrations were enriched in the Holocene alluvial aquifers with a dominance of As(III) species. It was generally agreed that reductive dissolution of Fe oxyhydroxides was the main mechanism for the release of As into groundwater coupling with the presence of organic matters and microbial activities as principal factors. A new model has also been suggested to explain how arsenic can naturally contaminate groundwaters far from the ultimate source with transport of As by active tectonic uplift and glaciatiion during Pleistocene, chemical weathering and deposition, and microbial reaction processes. In Korea, it has not been reported to be so serious As contamination, and from the national groundwater quality monitoring survey, only about $1\%$ of grounwaters have concentrations higher than $10{\mu}g/:L.$ However, it was revealed that $19.3\%$ of mineral waters, and $7\%$ of tube-well waters from Nonsan and Geumsan areas contained As concentrations above $10{\mu}g/:L.$. Also, percentages exceeding this value during detailed groundwater quality surveys were $36\%\;and\;22\%$ from Jeonnam and Ulsan areas, respectively, indicating As enrichment possibly by geological factors and local mineralization. Further systematic researches need to proceed in areas potential to As contamination such as mineralized, metasedimentary rock-based, alluvial, and acid sulfate soil areas. Prior to that, it is required to understand various geochemical and microbial processes, and groundwater flow characteristics affecting the behavior of As.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.201-210
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• 2000

Rock bridge in rock masses can be considered as one of several types of opening-mode fractures, and also it has been known to have a great influence on the stability of structures in rock mats. In the beginning of researching a rock bridge it used to be studied only in characteristics of its behavior, as considering resistance of material itself. However the distribution pattern of rock bridges, which can affect the stability of rock structures, is currently researched with a fracture mechanical approach in numerical studies. For investigating the effect of rock bridges on the development pattern of hydraulic fractures, the author analyzed numerically the stress state transition in rock bridges and their phenomena with a different pattern of the rock bridge distributons. From the numerical studies, a two-crack configuration could be defined to be representative of the most critical conditions for rock bridges, only when cracks are systematic and same in their length and angle. Moreover, coalescence stresses and onset of propagation stresses could be known to increase with decreasing s/L ratio or increasing d/L ratio. The effect of pre-existing crack on hydraulic fracturing was studied also in numerical models. Different to the simple hydraulic fracturing modeling in which the fractures propagated exactly parallel to the maximum remote stress, the hydraulic fractures with pre-existing cracks dial not propagate parallel to the maximum remote stress direction. These are representative of the tendency to change the hydraulic fractures direction because of the existence of pre-existing crack. Therefore s/L, d/L ratios will be identical as a function effective on hydraulic fractures propagation, that is, the $K_{I}$ vague increase with decreasing s/L ratio or increasing d/L ratio and its magnification from onset to propagation increases with decreasing s/L ratio. The scanline is a commonly used method to estimate the fracture distribution on outcrops. The data obtained from the scanline method can be applied to the evaluation of stress field in rock mass.s.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.89-95
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• 2007

This study was carried out to evaluate soil properties by regions from chestnut (Castanea crenata Sieb. et Zucc) stands in Gyeongnam province. Soil physical and chemical properties were measured from soil samples of top 20 em collected from three hillslopes (upper, middle, lower) of the chestnut stands in six regions (Jinjusi, Sacheonsi, Sancheonggun, Hadonggun, Goseonggun, Hapcheongun) where are major chestnut cultivation areas throughout the province. Soil properties were significantly different among regions (p<0.05), while were not significantly different among hillslopes (p>0.05). Soil bulk density, soil pore space, soil pH, organic matter content, total nitrogen, available phosphorus, and CEC were significantly different among regions (p<0.05). Soil bulk density was significantly lower (p<0.05) in Hadonggun ($0.96g/cm^3$ than in other regions ($1.12{\sim}1.22g/cm^3$). Soil pH was below pH 5.03 in most regions and Sancheonggun showed the lowest soil pH value (pH 4.62), followed by Jinjusi, Hadonggun, Hapcheongtm, Goseonggun, and Sacheonsi. Organic matter content was highest in Hadonggun (6.46%), while other regions ranged between 2.93% and 3.47%. Total nitrogen content showed a similar trend like the organic matter content. Available phosphorus was above 100 ppm in Jinjusi, Hadonggun and Sancheonggun, but Sacheonsi showed the lowest concentration (15 ppm) among the regions. Cation Exchange Capacity (CEC) was above 10 cmolc/kg in Goseonggun and Hadonggun, but below 8.6 cmolc/kg in Jinjusi and Hapcheongtm. Potassium content ranged between 0.07 and 0.14 cmolc/kg, and magnesium was above 0.66 cmolc/kg in all regions. The results indicate that soil property in chestnut stands was different among regions in Gyeongnam province. This suggested that the chestnut stands should be managed by the fertilization application reflected in the variability of regional soil property in chestnut stands.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.1-12
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• 1996

This study was aimed to provide understanding on the eco-physiological response of barley tillers as affected by fertilizer application level. Yield and yield contribution rate of tillers were investigated with the data of field experiments in the former Wheat and Barley Research Institute of Suwon, Korea from September 1982 to July 1984. The 50％ and 100％ increased rates of fertilizer application were compared to the local recommendation, which is 120 - 90 - 70kg /ha for N-P$_2$O$_{5}$-K$_2$O, to examine tiller dynamics under diverse fertilization scheme. With the increased rates, more mainstem leaves appeared and more effective tillers resulted from C3, 4P, 41, 2P1 and 3PP. Higher number and yield of grains per plant were also observed in the increased rates, though the number of grains and grain yield per ear were slightly lower than the recommended rate. The order of yield contribution by various tillers with the recommended rate and 50％ increment was mainstem, 1, 2, 11, 3, 21, 12, 22, 4 and C, but 1 and 11 contributed more than mainstem and 3 with the 100％ increased rate.e.