• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.31-46
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• 2024

Subterranean termite attacks on cajuput (Melaleuca cajuputi) seedling roots were widespread in several of Java's Perum Perhutani Forest Management Units. This attack was suspected to be related to the chemical components of the cajunput seedling roots. This study was conducted to determine the bioactivity of cajuput seedling root extract as an attractant for the subterranean termite Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae). The extraction process was performed according to ASTM D1108-96, and the extract was characterized using gas chromatography-mass spectrometry (GC-MS). Bioactivity testing of the extracts was carried out using attractiveness and no-choice feeding bioassays. The results showed that the average root extraction yield from cajunput seedlings was 4.94%. The attractiveness of the extract solutions at concentrations of 0.50%, 0.75%, and 1.00% were 45.33%, 62.00%, and 74.67%, respectively. The mortality rate of C. curvignathus termites ranged from 9.63% to 24.44%. Cajuput seedling root extract's lethal concentration 50 was 2.45% (non-toxic). GC-MS analysis showed that the extract contained linoleic acid, which has the potential to attract insects.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.2
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• pp.125-130
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• 2014

In order to evaluate the distributions of colloidal $^{210}Pb$ (half life = 22.2 years) and $^{210}Po$ (half life = 138 days) in subterranean estuary, we have measured $^{210}Pb$ and $^{210}Po$, for the first time, in the total dissolved (< $0.45{\mu}m$), true dissolved (<10 kDa), and colloidal ($10kDa-0.45{\mu}m$) phases in subterranean estuary of Hampyeong Bay in July 2010 and of Jeju Island in January 2011. The $^{210}Pb$ and $^{210}Po$ activities in groundwater were in the ranges of $0.21-2.52mBqL^{-1}$ and $0.12-2.07mBqL^{-1}$ for true dissolved phase and $0.10-1.71mBqL^{-1}$ and $0.03-0.97mBqL^{-1}$ for colloidal phase, respectively. The proportions of the colloidal phase to the total dissolved phase were $40{\pm}5%$ for $^{210}Pb$ and $28{\pm}5%$ for $^{210}Po$ in groundwater. This result indicates that colloids may play an important role in transporting trace elements through subterranean estuary into the coastal ocean.

• Journal of Conservation Science
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• v.37 no.3
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• pp.191-208
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• 2021

In this study, the status of damage by subterranean termites and their management according to the region and type of domestic wooden cultural properties were identified. This was based on the survey reports of agencies conducting regular nationwide and regional monitoring of subterranean termites. In addition, using geographical information system (GIS) based on the survey contents, a map was constructed of termite infestation and its progress on 2,805 wooden cultural properties that were surveyed nationwide. Based on the map produced, a total of 486 cases of termite infestation were confirmed in wooden cultural properties during 2018-2019, of which 143 cases (approximately 29.4%) were confirmed to be owing to the invasion of termites in the ground and infestation of wood materials. A web platform and an application using a mapping application program interface were created to increase accessibility to the investigated damage status data. The methods employed by each institution for investigating and monitoring the invasion of termites in the ground included the use of detection dogs, visual observation, installation of wood specimens made of pine, and microwave equipment. However, it was confirmed that monitoring and survey methods were not applied to determine the territorial range of the subterranean termite colonies. Accordingly, the use of dyeing and mark-release-recapture methods were deemed necessary to understand the current status, such as calculating the scope of the target wooden cultural property, when monitoring subterranean termite colonies.

• Animal Systematics, Evolution and Diversity
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• v.23 no.2
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• pp.155-167
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• 2007

As a result of the faunistic study on the subterranean cyclopoid copepods, four species of three genera in the family Cyclopidae are reported from nine limestone caves and a lava tube in South Korea: Megacyclops magnus (Marsh, 1920), Acanthocyclops orientalis Borutzky, 1966, A, robustus (Sars, 1863) and Diacyclops suoensis Ito, 1956, all of them new to Korean fauna. This paper deals with the taxonomic accounts and illustrations of the four species with the redescription of A. orientalis. This is the first taxonomic study on the cave-dwelling cyclopoid copepods from Korea.

• Computational Structural Engineering
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• v.2 no.2
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• pp.53-62
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• 1989

In recent times, the subterranean caverns for storing crude oils and oil products are increasingly needed. The elasto-VIScoplastic DYNamic finite element analysis program(VISDYN) has been developed in order to investigate dynamic responses of the storage cavity. And validity of the program is studied through a numerical example. Mohr-Coulomb yield criterion is adopted and associated flow rule is assumed. Geometrically nonlinear behaviour is taken into account using a total Lagrangian formulation. In dynamic deformation reponses, the difference between the steady state displacements and the unsteady state ones by the static analysis can be neglected.

• YAKHAK HOEJI
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• v.39 no.2
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• pp.141-147
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• 1995

Four steroids have been isolated from the subterranean parts of Smilax nipponica Miquel (Liliaceae). The structures of these compounds were characterized on the basis of chemical and speectral data. They were $\beta$-sitosterol, $\beta$-sitosterol-3-O-$\beta$-D-glucopyranoside, neotigogenin-3-O-$\beta$-D-glucopyranoside and a new steroidal saponin designated as smilanippin A which was elucidated as neotigogenin-3-O-$\beta$-D-fucopyranosyl(1$\rightarrow$6)-$\beta$-D-glucopyranos ide.

• Journal of Plant Biology
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• v.12 no.1
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• pp.1-6
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• 1969

General components, free sugars, and free amino acids about Zostera marina which is much distributing and producing along the coastlines of Korea have been separated and identified through Ion exchange resin and Paper chromatography method. So distrigushed are sugars contained that this was quantitated by Bertrand method. 1) The result of the general component analysis of Zostera marina shows that there are much free sugars. 2) According to Bertrand method sugar containment quantitated from terrestrial stem and subterranean stem on Po-hang and Ko-hung areas is much more in terrestrial stem than subterranean stem. 3) Seven kinds of sugars are used in experiments(Table 2) among there glucose, fructose and sucrose which keep the sweetness are very much contained. 4) Shown in Fig. 3 ten kinds of free amino acids inspected from experimental liquid by Paper chromatography are separated, which are known, and one spot which in unknown is additionally separated, and in which four kinds of essential amino acid to nutrient are contained.

• Journal of Wetlands Research
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• v.11 no.1
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• pp.99-104
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• 2009

Gotjawal forest refers to the forest covering the rocky area of "AA Lava" on Jeju Island of South Korea. In this article it is shown that Gotjawal forest is an internationally important wetland under the Ramsar Convention. Gotjawal forest should be regarded as a wetland because it is a subterranean hydrological system, which is classified as wetland under the Ramsar Convention. And Gotjawal forest is an internationally important wetland because it is the representative wetland type of Jeju region with hydrological importance, and because it supports rare species of plants.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.301-306
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• 1998

In order to improve cultivation technuque of C. lanceolata, natural ABA was treated with foliar application periodically during differenctitation of node. The higher is concentration and the earier its foliar application was, the shoter plant height was. Especially, when $10mg;.L{-1}$ of ABA was treated at differentiated stage of 3rd node, plant height was inhibited to 60% of control. But leaf length, leaf width, and number of branches have no significant differnence in comparison wiht control. The fresh weight of subterranean part was similar to control independent of treat-time in the case of $10mg;.L{-1}$. When 1,5 and $10mg;.L{-1}$ of ABA were treated at initial differentiated node stage, plant height inhibited to 20~30% of control, but subterranean part was similar to control. All treatement showed slight antitumor activity by the P388 cytotoxic screening test.

• Animal Systematics, Evolution and Diversity
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• v.39 no.3
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• pp.123-126
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• 2023

Members of Allobathynella Morimoto and Miura, 1957 and Hangangbathynella Park and Cho, 2013 belong to the family Parabathynellidae Noodt, 1965 exclusively inhabit subterranean environments including caves, springs, and interstitial groundwater. Among them, two parabathynellid species, Allobathynella cheongdoensis Park and Cho, 2016 and Hangangbathynella taechooni Park and Cho, 2013, have been reported in the hyporheic zones of the Nakdonggang and Namhangang Rivers in South Korea, respectively. To evaluate gene markers as diagnostic characters, we determined mitochondrial cytochrome c oxidase subunit 1 (CO1) and nuclear 18S rDNA from the topotypes of two Korean parabathynellid species, and then analyzed the genetic divergence among the two parabathynellids and their congeners. Additionally, we provided their habitus photographs and a brief discussion of the usefulness of the two marker regions for both genera as DNA barcodes.