• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.172-178
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• 2006

The dynamics of bacterial populations belonging to $\alpha\;\beta\;\gamma-subclass$ proteobacteria, Cytophaga-Flavobacterium (CF) group and sulfate reducing bacteria (SRB) in water column of the middle reaches of Nakdong River depending on sediment harvesting were analyzed by fluorescent in situ hybridization (FISH) at sediment harvesting site (near the Seongju bridge) and non-sediment harvesting site (near the Gumi bridge). In addition, some physico-chemical parameters such as temperature, pH, $chi-\alpha$ and electrical conductivity were measured. Regarding the number of total cell counts, cells stained by DAPI, there were no substantial quantitative differences between both sites, but those fluctuation at sediment Harvesting site was greater. And also the ratios of CFgroup and SRB to total cell counts tend to increase at sediment harvesting site with higher $chl-\alpha$, maybe due to the resuspension of sediment into water column. But the total proportion of all determined bacterial populations to total cell counts were greater at non-sediment harvesting site, compared with those at sediment harvesting site. Since the detectibility of bacteria by FISH depends on their metabolic activity, those lower proportion at the sediment harvesting site implies that sediment harvesting may lead to malfunction of those bacteria respect to nutrient recycling and subsequently negative effects on microbial food web.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.8
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• pp.1286-1298
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• 2008

This study was attempted to examine the indigo dyeing technique in the latter Joseon Dynasty, and to find diachronic specifics in the indigo dyeing method from 17C to 19C. The results are as follows: First, There were 2 kinds of indigo species-Yoram(Polygonum tinctorium Lour.) and Sungram(Isatis tinctoria L.)-in the latter Joseon Dynasty. Dangram was preferred in particular among Yoram species because of its high dyeing efficiency. Sungram was mainly used for making Jeon(indigo sediment). Second, Yoram cultivation took the following order: Sowing in April${\rightarrow}$planting out in June${\rightarrow}$harvesting leaves in August${\rightarrow}$collecting seeds in September. Sungram had more harvesting times and wider harvesting period than Yoram. Third, all indigo dyeing methods were grouped into two categories, one was temporary dyeing method, the other was permanent dyeing method. Mixture dyeing of the boiled and the raw, raw leaves dyeing, and fermentation dyeing belonged to the temporary dyeing. Jeon dyeing and Gaeogi dyeing belonged to the permanent dyeing. Finally, diachronic specifics from 17C to 19C were as follows: Decline in the mixture dyeing of the boiled and the raw, development in the raw leaves dyeing, continuance of the fermentation dyeing, and naturalization of Jeon dyeing technique.

• Water Engineering Research
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• v.2 no.4
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• pp.269-276
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• 2001

The project concentrates on an hydrological analysis. The analysis consists of rainfall, infiltration, Determination of runoff and sediment yield. The risque of erosion and the control measures are related to the slopes and land use. Therefore the first approach to erosion must be correct land use based on land classification. Basically there are two types of mechanical protection works; Drainage and Storage. Realization of a drainage system will be very costly and therefore temporary storage is preferred. For farmland in flat areas hardly any measures are needed. For farmland on slopes temporary storage can be effected by applying tillage with ridges within contour bunds. Along roads infiltration pits should be constructed and in areas with houses, the solution to avoid runoff will be water harvesting.

• The Korean Journal of Malacology
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• v.26 no.4
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• pp.267-273
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• 2010

From January to December 2007, we have investigated sediment types, environmental factors and density of clam Ruditapes philippinarum inhabited at Oeri, Naeri, Jonghyeon and Bangmiri tidal flats in Gyeonggi Bay off the west coast of Korea. Sediment types of Oeri and Jonghyeon were characterized with well sorted muddy sand. In contrast, Bangmiri tidal flat was mainly composed of poorly sorted gravelly muddy silt and Naeri was characterized with very poorly sorted muddy-sandy gravel. During the course of study, the surface water temperature, salinity, dissolved oxygen and pH ranged 3.2 to $27.0^{\circ}C$, 21.7 to 33.3 ‰, 5.6 to 12.7 mg/l and 7.36 to 8.82, respectively. The suspended solid (SS) ranged from 3.2 to 1,266.0 mg/l and chlorophyll-a level in the water column ranged $0.3-36.1{\mu}g/l$, respectively. The density of clam in the study areas was mainly determined by the harvesting activities rather than the types of substrate. Relatively higher density of clam was observed in Oeri and Bangmiri where the clam seeds were sowed by the villagers. Condition factor of clams were found to be higher in Oeri where the substrate sorting was better with higher level of chlorophyll a. It was believed that sediment types and the level of available food the two governing factors controlling the density and growth of clam in Gyeonggi Bay.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.193-193
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• 2022

Cowpea(Vigna unguiculata L. Walp) has a low fat and protein content and a relatively high starch content, so it is mainly used in various ways for song-pyeon sediment, rice-cake paste, and porridge. In Yeonggwang-gun, Jeollanam-do, cowpea for seed production is being cultivated for the localization of raw material for Rice cake with ramie leave. A cowpea variety 'Jang-Alchan' was improved from the cross between IT145373 and IT145391 at the JARES in 2019. 'Jang-alchan' has an erect plant with an intermediate plant habit, light purple-colored corolla, and heart-shaped leaflets. 'Jang-alchan' has an orange-yellow seed seed-surface of faint luster, and brown and straight pods when matured. The stem length of 'Jang-alchan' was 48cm, 9cm longer than that of the control cultivar 'Okdang' and the 100-seed weight was 14.1g. The weight ratio of the seed coat for the entire seed was 11.2%, which was 0.2%p lower than that of the control cultivar. Field resistance of 'Jang-alchan' to leaf and systemic diseases was similar to that of the control cultivar. Is field resistance of 'Jang-alchan' to lodging was slightly lower than that of the control cultivar. The average yield of 'Jang-alchan' was 1.85ton per hectare, which was 14% higher than that of the control cultivar 'Okdang', 'Jang-Alchan' does not require the installation of an espalier-net and is taller than the existing supplied 'Okdang', so it can be harvested by combine harvesting. In addition, it is expected to contribute to the localization of raw material grains for regional specialties as it can be cultivated over a large area.

• Journal of Aquaculture
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• v.7 no.4
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• pp.251-264
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• 1994

To study the causes of occurring toxic dinoflagellate Alexandriwn species, an experiment was undertaken in Jinhae Bay shellfish harvesting areas. The water and sediment samples were collected to record the abundance of Alexandriwn species, and to study the distribution and the germinability of those benthic cysts from September 1993 to July 1994. Alexandrium species were began to appear at all the sample stations after January, and reached maximum concentration (530 cells/l) at Taekok station (Chilcheon-do) in March 1994. Alexandrium cysts were also found at every station surveyed, of which several sites showed the higher concentration of 700-800 $cysts/cm^3$ at the upper sediment profile (0-4cm), but the concentrations were wide range of 100-800 $cysts/cm^3$. The results of each sampling season showed a great difference in the cyst germination experiments, were potentially high in cold season; $72.5\%$ (Jan.), $68\%$ (Apr.),$44\%$(Jul.), and $9\%$ (Oct.). These results suggested that germination of Alexandrium resting cysts in 15 m depth of coastal waters in Jinhae Bay would be controlled by a seasonal endogenous clock instead of the general environmental factors like temperature. Therefore, it is possible that Alexandrium species could be abundant by the germination of resting cysts in cold season, and contribute to the regional paralytic shellfish poisoning (PSP) toxification.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.28-30
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• 2005

Because of high population diversity in soil microbial communities, it is difficult to accurately assess the capability of biodegradation of toxicant by microbes in soil and sediment. Identifying biodegradative microorganisms is an important step in designing and analyzing soil bioremediation. To remove non-important noise information, it is necessary to selectively enrich genomes of biodegradative microorganisms fromnon-biodegradative populations. For this purpose, a stable isotope probing (SIP) technique was applied in selectively harvesting the genomes of biphenyl-utilizing bacteria from soil microbial communities. Since many biphenyl-using microorganisms are responsible for aerobic PCB degradation In soil and sediments, biphenyl-utilizing bacteria were chosen as the target organisms. In soil microcosms, 13C-biphenyl was added as a selective carbon source for biphenyl users, According to $13C-CO_2$ analysis by GC-MS, 13C-biphenyl mineralization was detected after a 7-day of incubation. The heavy portion of DNA(13C-DNA) was separated from the light portion of DNA (12C-DNA) using equilibrium density gradient ultracentrifuge. Bacterial community structure in the 13C-DNAsample was analyzed by t-RFLP (terminal restriction fragment length polymorphism) method. The t-RFLP result demonstates that the use of SIP efficiently and selectively enriched the genomes of biphenyl degrading bacteria from non-degradative microbes. Furthermore, the bacterial diversity of biphenyl degrading populations was small enough for environmental genomes tools (metagenomics and DNA microarrays) to be used to detect functional (biphenyl degradation) genes from soil microbial communities, which may provide a significant progress in assessing microbial capability of PCB bioremediation in soil and groundwater.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.6
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• pp.764-772
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• 2018

It is necessary to explore the possibility of alternative habitats and research the characteristics of basic habitats due to seeding, culturing and harvesting of blood clams (Tegillarca granosa) in tidal flats. Currently, dependence on naturally occurring spat is much higher than in other species, which may lead to a reduction in biological resources. In this study, we selected a total of 5 sites (Changgi, Hopo in Cheonsu Bay and Dangsan, Sachang, Wangsan in Garolim Bay) and examined habitat suitability factors for suitable site selection. Also, we considered the relationship of habitat suitability factors (Environment: water content, organic content; survival: mud content, mean size; growth: chlorophyll a). As a result, Wangsan had the highest score of the main habitat of blood clams (Habitat suitability score, Wangsan: 87; Dangsan: 86; Sachang: 81; Hopo: 78; and Changgi: 73). The sediment in Garolim Bay was fine-grained and the seasonal variation was lower than Cheonsu Bay. Therefore, it is considered that Garolim Bay is more suitable as a potential area and easy to utilize the space. In the future, search and selection of potential suitable sites could be considered to solve problems caused by the reduction of biological resources and the production for blood clams.