• ALGAE
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• v.27 no.4
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• pp.225-234
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• 2012

Zygnema is a conjugating filamentous green algal genus that is distributed in a broad range of freshwater habitats, from sea level to alpine summits. Although more than 150 species have been described worldwide, their taxonomy remains unclear, probably owing to their relatively simple morphology. We investigated the detailed morphology of Korean Zygnema species, combined with analysis of the plastid psbA gene from 22 specimens of the genus and putative relatives, in order to develope a key to their identification and isolation, and to determine their relationships. We recognized two species of Zygnema; Z. insigne and Z. leiospermum, based on morphological characters such as width of the vegetative cell, position of zygospores, dimensions and form of spores, shape of female gametangia, and color of mesospores. The analysis of psbA data was consistent with morphological comparison. The pairwise divergence between two species was 3.7-4.1% (34-38 bp) in psbA sequences. The phylogeny of psbA revealed the monophyly of Z. insigne and Z. leiospermum together with two isolates of Z. circumcarinatum from Germany and Scotland. This is the first report on the psbA gene phylogeny of Zygnema.

• Korean Journal of Plant Taxonomy
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• v.50 no.3
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• pp.351-355
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• 2020

Argyreia gyrobracteata Traiperm & Chitchak (Convolvulaceae) is newly recorded in Vietnam. It is similar to A. mekongensis Gagnep & Courch in having a white campanulate corolla but differs from that species by having whitish surface of the abaxial leaf, narrowly lanceolate or linear-oblong, curly, rolled up the bract with a longer length of the petiole and a shorter pedicel. It was previously known only in Thailand, but was recently found in Lam Dong Province, Vietnam, for the first time. The present study provides a detailed description, colorful photos and the distribution of the species. Furthermore, a comparison of the diagnostic characters between this species and a related species in Vietnam, A. mekongensis Gagnep & Courch, is provided.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.739-742
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• 2003

We have compared 2-D and 3-D fluid simulation results of alternating current plasma display panel (AC-PDP) cell with experimentally measured two kinds of excited Xe species $Xe^{\ast}(^{3}P_{1})$ and $Xe^{\ast}(^{3}P_{2})$ characteristics. Although direct experimental access and diagnostics of the discharge in a PDP cell is problematic due to the small cell size, some of experimental technologies have made it possible to diagnose the behavior of excited Xe species [1, 2]. The simulation shows the similar characteristics to the experimental results in the excited Xe species density distribution and the number of excited Xe atoms in anode and cathode region. In certain cases, we obtained the arch-shaped discharge path between two sustain electrodes due to the additional pulse applied to address electrode analogous to experiment. This long path discharge induced higher luminous and discharge efficiency compared to the standard case.

• Journal of Ecology and Environment
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• v.31 no.4
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• pp.277-290
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• 2008

In the past two decades Mikania micrantha Kunth, a climbing plant species originating from tropical America, has spread across Taiwan. It can now be found frequently in the lowlands and lower mountain areas up to 1,000 m a.s.l. in the centre and south of the island. Mikania micrantha is considered a problematic invasive alien plant species which is said to cause economical as well as environmental damage. This study investigated the ecological site characteristics of M. micrantha in Taiwan. 112 vegetation surveys were carried out in habitats where the alien plant was present. A comparison between sites with a high and a low abundance was carried out in order to assess which factors especially influence the extensive spread of the plant. Furthermore, the influence of disturbances was examined. Results showed that Mikania micrantha grows very dense in habitats which are characterized by good light conditions combined with vertical structures, such as trees. Results revealed that this invader occurs most frequently in agricultural fallows and wastelands, but it could hardly be found in the intensively managed plantations in the investigation area. Results provide great evidence that the plant is strongly influenced by disturbances, but only if impacts occur rarely.

• Korean Journal of Plant Taxonomy
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• v.44 no.1
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• pp.9-12
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• 2014

Talipariti simile (Blume) Fryxell, Malvaceae is reported as new record from Vietnam. The plant can be differentiated from its allied species T. macrophyllum (Roxb. ex Hornem.) Fryxell in having glabrescent stems with purplish and smaller hairs, lanceolate-oblong and smaller stipules and ovoid capsules which are devoid of apicule or beaks. Taxonomic description, line drawing and color photographs have been provided to add to the species identification. Furthermore, comparison of the diagnostic characters between this species and the above mentioned related species is made.

• Mycobiology
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• v.39 no.3
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• pp.194-199
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• 2011

Pepper anthracnose caused by Colletotrichum species is one of the most important limiting factors for pepper production in Korea, its management being strongly dependent on chemicals. The aim of this work was to evaluate the possibilities of using silver nanoparticles instead of commercial fungicides. In this study, we evaluated the effect of silver nanoparticles against pepper anthracnose under different culture conditions. Silver nanoparticles (WA-PR-WB13R) were applied at various concentrations to determine antifungal activities in vitro and in the field. The application of 100 ppm concentration of silver nanoparticles produced maximum inhibition of the growth of fungal hyphae as well as conidial germination in comparison to the control in vitro. In field trials, the inhibition of fungi was significantly high when silver nanoparticles were applied before disease outbreak on the plants. Scanning electron microscopy results indicated that the silver nanoparticles caused a detrimental effect on mycelial growth of Colletotrichum species.

• Journal of Species Research
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• v.9 no.3
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• pp.269-272
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• 2020

In this study, a species of Rhabdocoela is reported from Korea for the first time. The kalyptorhynch Alcha sinensis Wang & Hu, 2019, was collected from the intertidal zone of Anmyeon Island. Compared to the original study on A. sinensis and previous studies on A. evelinae, we provide additional detail of these two species through pictures of the stylet and a improved description of the prostate stylet type III, which is composed of a bowtie-shaped base and two pairs of heteromorphic plates with fringed or serrated edges. Two plates are also provided with a rounded "blade". Also, we discuss the importance of the prostate stylet type III as a diagnostic character. After a thorough comparison of the descriptions of A. evelinae Marcus, 1949, and A. sinensis, we conclude that the Korean specimens belong to the latter species. Finally, we discuss the difficulties of interpreting diagnostic characters of the small and complex prostate stylet type III within the genus Alcha.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.44-44
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• 2014

Yeasts were isolated from wild flowers of some islands and mountains such as Jeju-do, Ulleungdo, Yokjido, Seonyudo and Gyejoksan, Oseosan, Beakamsan and Deogyusan in Korea and were identified by comparison of nucleotide sequences for PCR-amplified D1/D2 region of 26S rDNA or internal transcribed pacer(ITS) 1 and 2 including 5.8S rDNA using BLAST. Seventy two yeast strains of two hundred eighty nine species were isolated from wild flowers in islands and mountains, Korea. Among them, Cryptococcus species were isolated the most dominantly, and Metschnikowia reukaufii were also isolated thirty species, 10.3% of total strains. Twenty-three species including Cryptococcus aureus were overlapped between yeast strains of the islands and mountains. Some physiological functionality of the culture broth and cell-free extracts from two hundred eighty nine yeast strains were determined. The supernatant of Candida sp. 78-J-2 showed antioxidant activity of 22.5%, and supernatant of Metschnilowia reukaufii SY44-6 showed anti-gout xanthine oxidase inhibitory activity of 49.6% and whitening tyrosinase inhibitory activity of 38.4%, respectively.

• Korean Journal of Plant Taxonomy
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• v.46 no.1
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• pp.55-59
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• 2016

Justicia kampotiana Benoist (Acanthaceae) is reported as a new record for the flora of Vietnam. This species differs from its allied species J. ingrata Benoist in having corolla outside pubescent, tubes slightly longer than limbs and considerably shorter petioles. Description, line drawing and color photographs are provided for species identification. Furthermore, a comparison of the diagnostic characters with those of related species is made.

• Nuclear Engineering and Technology
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• v.24 no.3
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• pp.228-235
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• 1992

Some soluble species may not be solubility-limited or congruent-released with the matrix species. For example, during the operation of the nuclear reactor, the fission products can be accumulated in the fuel-cladding gap, voids, and grain boundaries of the fuel rods. In the waste package for spent-fuel placed in a geologic repository, the high solubility species of these fission products accumulated in the“gap”, e.g. cesium or iodine are expected to dissolve rapidly when ground water penetrates fuel rods. The time and space dependent mass transport for high solubility nuclides in the gap is analyzed, and its numerical illustrations are demonstrated. The approximate solution that is valid for all times is developed, and validated by comparison with an asymptotic solution and the solution obtained by the numerical inversion of Laplace transform covering the entire time span.