• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.86-107
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• 2019

The vascular plants of Island Dolsando, located in Yeosu-si, Jeollanam-do were surveyed 15 times from June 2017 to March 2018. Based on the collected specimens, there were 570 taxa; 113 families, 338 genera, 517 species, 1 subspecies, 49 varieties and 3 formas respectively. 18 taxa of Korean endemic species such as Asarum maculatum Nakai were found. There were total 90 taxa of floristic regional indicator plants specially designated by the Ministry of Environment (Level V to I), 4 taxa of rare plants and 8 taxa of endangered plants including Ligularia taquetii (H. $L{\acute{e}}v.$ & Vaniot) Nakai.

• Mycobiology
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• v.47 no.2
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• pp.191-199
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• 2019

Most of lichens are formed by Ascomycota, less than 1% are lichenized Basidiomycota. The flora investigation of lichenized Ascomycota of South Korea has been well studied in the past three decades; however, prior to this study, none of basidiolichens was discovered. During the recent excursion, an unexpected clavarioid basidiolichen, Sulzbacheromyces sinensis was collected. Morphology and ecology has been recorded in detail. DNA was extracted, and ITS, 18S, 28S nuclear rDNA were generated. In order to further confirm the systematic position of the Korean specimens, maximum likelihood and Bayesian inference analysis including all the species of the order Lepidostromatales were conducted based on the ITS. As a result, the phylogenetic tree of the order Lepidostromatales was reconstructed, which differed from the previous studies. The inferred phylogenetic tree showed that species of Sulzbacheromyces in three different continents (Asia, South Africa and South America) were separated into three clades with support. In this study, the species worldwide distribution map of Lepidostromatales was illustrated, and S. sinensis had a widest distribution range (paleotropical extend to the Sino-Japanese) than other species (paleotropical or neotropical). Prior to this study, the range of distribution, southernmost and northernmost points and the fruiting time of S. sinensis were recorded, and the genus Sulzbacheromyces was firstly reported from Korean peninsula and Philippines.

• Korean Journal of Plant Taxonomy
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• v.49 no.2
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• pp.179-197
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• 2019

This study presents the flora of vascular plants on Oenarodo Island, located in Goheung-gun, Jeollanam-do, Korea. A list of vascular plants was created based on the herbarium of the National Biological Resource Center (NIBR) and the Daejeon University Biology Department herbarium (TUT) collected from field surveys. Based on specimens collected in the field during 21 separate field trips amounting to a total of 21 days conducted between March of 2015 and October of 2017, there are 587 taxa on Oenarodo Island, consisting of 122 families, 364 genera, 538 species, six subspecies, 41 varieties, and two forms. Among the collected plants, those endangered were four taxa, those endemic were 14 taxa, floristic regional indicator plants specially designated by the Ministry of the Environment amounted to 137 taxa, and those naturalized amounted to 46 taxa.

• Korean Journal of Plant Taxonomy
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• v.51 no.4
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• pp.378-385
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• 2021

Saussurea taquetii reported from Jejudo Island is either treated as a synonym of S. japonica or is recognized as a distinct taxon. Saussurea japonica and S. pulchella belong to the sect. Theodorea by having peculiar outer phyllaries with pale purplish scarious apical appendages; they are closely related to each other morphologically and are known to occur widely throughout the Korean Peninsula. To assess the taxonomic status of S. taquetii, we investigated representative populations of S. taquetii from jejudo Island, Korea, and S. japonica from Kyushu in Japan. We conducted a comparative study morphologically using specimens of three species from KH, CNU, and TI. Saussurea taquetii is very similar morphologically and ecologically to S. japonica in Kyushu. Unlike previous floristic treatments, we concluded that the two taxa, S. pulchella and S. taquetii, occur on the Korean Peninsula and on jejudo Island, respectively.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.63-70
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• 2019

Objective : Arnebiae Radix, the roots of Arnebia euchroma (Royle) Johnst. or A. guttata Bunge, is a well-known traditional herbal medicine in East Asia. In the Korean Pharmacopoeia, three authentic species, including two Arnebia and Lithospermum erythrorhizon Sieb. et Zucc. have recognized as a Lithospermi Radix. But, the morphological and taxonomic information of two authentic Arnebia species lacks date since their distribution and difficulty of accessing the natural habitats. Methods : A full description of the external morphological characteristics of vegetative and reproductive organs in the original plants was carried out using digital calipers and stereoscope. For providing their taxonomic and nomenclatural synonyms, we reviewed various plant checklists and taxonomic literature. Results : This study provides taxonomic information of A. euchroma and A. guttata based on a morphological examination of authentic plant individuals and field observations. Detailed descriptions of the two Arnebia species, major quantitative and qualitative characteristics, nomenclatural reviews, distribution maps, and lists of voucher specimens examined are provided. The shape of leaves, root length, stem number, calyx length and pubescence as well as corolla color were useful characteristics for identification. Moreover, we confirmed that A. euchroma and A. guttata are clearly heterostylous species. Conclusion : Our research provides valuable basic information that could be used as quality control for distinguishing between Arnebiae Radix and its adulterants. These results will help in the understanding of authentic plants and also provide the verified materials and voucher information.

• The Journal of Advanced Prosthodontics
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• v.15 no.4
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• pp.189-201
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• 2023

PURPOSE. The aim of this study was to investigate the mechanical properties of three-dimensional (3D) printed denture base resin incorporating microcapsules containing plant essential oils. MATERIALS AND METHODS. Denture base specimens containing up to 3% w/v essential oil microcapsule powders (MCPs), i.e., eucalyptus, geranium, lavender, menthol, and tea tree, in two resins (Detax and NextDent 3D+) were 3D printed using two printers (Asiga and NextDent 5100). The dispersion and interaction of the MCPs in the resin were assessed by SEM while the mechanical properties of the incorporated denture base including flexural strength (MPa), flexural modulus (MPa), Vickers hardness (VHN), and surface roughness (Ra) were also subsequently evaluated. Statistical analysis of any differences in mean values was determined using a two-way ANOVA with Tukey's post hoc testing (α = .05). RESULTS. The spherical shape of the MCPs was maintained during the mixing and polymerization/printing process. However, the Detax-Asiga group showed significant agglomeration of the MCPs even at the lowest MCP concentration levels (0.5% w/v). Overall, as the microcapsule concentration increased, the mean flexural strength decreased, though the menthol MCP groups remained compliant with the ISO standard. The flexural modulus and harness remained relatively unchanged, and the flexural modulus complied with the ISO standard regardless of the MCP concentration. Surface roughness increased with the addition of the MCPs but also remained below that required for clinical acceptance. CONCLUSION. Incorporation of microencapsulated plant essential oils into 3D printed denture base resin was successfully achieved. While incorporation negatively influenced flexural strength and surface roughness, little effect on flexural modulus and Vickers hardness was demonstrated.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.27-27
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• 2020

Daphne L. (Thymelaceae) comprises about 95 species distributing worldwide from N Africa, N India, SE Asia to E Asia and the coast of the Mediterranean of Europe. In Korea, five species of this genus have been described. In this study, we included four species (D. genkwa, D. pseudomezereum, D. kiusiana, D. jejudoensis) from Korea, excluding cultivated D. odora. The morphological characters through local surveys and the re-classification of the specimens collected in the Korea National Herbarium (KH) were carried out and distribution maps for each taxon were also prepared. The major characters include habit, trichomes in winter bud, leaf, and twig, phyllotaxis, inflorescence, size of calyx lobe and trichomes in the calyx tube, etc. The distribution map showed that D. genkwa is mainly distributed in the coastal area of Hwanghaenam-do, Pyeongannam-do, Jeollabuk-do and Jeollanam-do, whereas D. pseudomezereum is distributed in the limestone zone of Gangwon-do, Jeollabuk-do, and Gyeongsangbuk-do. Similarly, D. kiusiana is mostly found in Jeollanam-do, Gyeongsangnam-do, and Jeju-do. In addition, D. jejudoensis is known to be distributed in forests of Murueng, Andeok, and Seonheul-ri in Jeju-do, but recently, new habitat is discovered in the island forest areas of Jeollanam-do. However, some of these individuals showed the characteristics of D. kiusiana, thus before come to any conclusion detailed taxonomic review of D. jejudoensis and D. kiusiana is required.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.4
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• pp.146-153
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• 2023

This study aimed to conduct a comprehensive survey of social wasp diversity and its impacts on remote Ulleungdo Island, South Korea. A total of 12 wasp traps were placed across the island, and specimens were collected monthly from May to October. Additional collection was conducted by thoroughly inspecting the areas surrounding the traps. The traps yielded a total of 5,068 individuals, representing two genera and two species. A total of 3,961 Vespa simillima simillima Smith individuals (78.2%) were collected, and 1,107 individuals (21.8%) were identified as Vespula flaviceps flaviceps Smith. Additionally, five individuals of Polistes snelleni de Saussure were collected through sweeping, bringing the total to 5,132 individuals of three genera and three species. It is worth noting that our findings indicate potential misidentifications in the species list of Vespidae found in the literature. Emergency services call centers reported the removal of 60 social wasp nests on Ulleungdo Island between 2018 and 2022, with the highest number of reports occurring from July to September, accounting for 87% of all cases. Dodong-ri and Jeodong-ri, with the highest populations, reported the most incidents, although fortunately, there have been no recent injuries. Past incidents involving the destruction of dried squid products by Vespula species have resulted in significant economic losses, underscoring the need for preventative measures. Furthermore, ongoing surveillance of hornet invasions is essential to safeguard the Jangwon bees being reared on Ulleungdo Island.

• Journal of Mechanical Science and Technology
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• v.17 no.3
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• pp.400-408
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• 2003

A study on the progressive inelastic deformation behavior of the 316 L stainless steel cylindrical structure with plate-to-shell junction under moving temperature front was carried out by structural test and analysis. The structural test intends to simulate the thermal ratcheting behavior occurring at the reactor baffle of the liquid metal reactor as free surface of hot sodium pool moves up and down under plant transients. The thermal ratchet load that heats the specimen up to 550$^{\circ}C$ was applied repeatedly and residual deformation was measured. The thermal ratcheting test was carried out with two types of cylindrical structures, one with plate to-shell junction and the other without the junction to investigate the effects of the geometric discontinuities on the global ratcheting deformation. The temperature distributions of the test specimens were measured and were used for the ratcheting analysis. The ratchet deformations were analyzed with the constitutive equation of the non-linear combined hardening model. The analysis results were in good agreement with those of the structural tests.

• Journal of Ocean Engineering and Technology
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• v.13 no.3 s.33
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• pp.100-107
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• 1999

Due to the high temperature and pressure, the materials of pipeline in power plant are degraded by creep damage. So far, many conventional measurement techniques such as replica method, electric resistance method, adn hardness test method for creep damage have been used. Among them, the replica method has mainly been used for the inspection of components. But this technique is restricted to the applications at the surface of the objects and cannot be used to material inside. In this paper, the measuring methods of evaluation by using ultrasonic attenuation and electric resistance for the creep detection of creep damage in the form of cavities on grain boundaries or intergranular microcracks were carried out. Absolute measuring method of quantitave ultrasonic attenuation technique for 1Cr0.5Mo material degradation was analyzed for determining the creep degradation steps using life prediction formula. As a result of measurement for creep specimens, we founded that the coefficient of utrasonic attenuation was increased as the increase of creep life fracton(${phi}c$) and the decreasing rate of wlwctric resistance was also increased.