• The Plant Pathology Journal
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• v.27 no.2
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• pp.183-186
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• 2011

During the summer of 2005, specimens of soybean cultivars (Daepung, Daewon, Hwanggeum and Taegwang) showing frogeye leaf spot (FLS) were obtained from various areas in Korea. Eight isolates identified as Cercospora sojina were inoculated on the adaxial leaf surfaces of 63 Korean soybean cultivars; the disease responses to each isolate were evaluated 14 days and 21 days after inoculation. Based on the disease responses (resistant or susceptible) of the cultivars by the isolates, a set of cultivars (Anpeong, Bogwang, Cheongdu No. 1, Cheongja No. 3, Dachae, Daemang, Jangwon, Namhae, Sowon, Taegwang) were selected and inoculated with seven isolates for further testing pathogenic variance. Interestingly, 6 out of 7 tested C. sojina isolates revealed differential ability in infecting different soybean cultivars. This result may indicate the possibility of new race occurrence or pathogenic variation; this also presents evidence for prevalent FLS occurrence during humid and hot weather in Korea.

• Mycobiology
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• v.48 no.4
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• pp.263-275
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• 2020

Phlebopus spongiosus is a well-known edible ectomycorrhizal mushroom indigenous to southern Vietnam. The mushroom specimens collected from northern Thailand in this study were identified as P. spongiosus. This identification was based on morphological characteristics and the multi-gene phylogenetic analyses. Pure cultures were isolated and the relevant suitable mycelial growth conditions were investigated. The results indicated that the fungal mycelia grew well on L-modified Melin-Norkans, and Murashige and Skoog agar all of which were adjusted to a pH of 5.0 at 30 ℃. Sclerotia-like structures were observed on cultures. The ability of this mushroom to produce fruiting bodies in the absence of a host plant was determined by employing a bag cultivation method. Fungal mycelia completely covered the cultivation substrate after 90-95 days following inoculation of mushroom spawn. Under the mushroom house conditions, the highest amount of primordial formation was observed after 10-15 days at a casing with soil:vermiculite (1:1, v/v). The primordia developed into a mature stage within one week. Moreover, identification of the cultivated fruiting bodies was confirmed by both morphological and molecular methods. This is the first record of P. spongiosus found in Thailand and its ability to form fruiting bodies without a host plant.

• Animal Systematics, Evolution and Diversity
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• v.20 no.2
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• pp.171-178
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• 2004

Two oxytrichid ciliates collected from the two habitats (soil under pine forest near beach and sewage treatment plant) in Korea were identified as Oxytricha balladyna Song and Wilbert, 1989 and O. longa Gelei and Szabados, 1950. These species are reported in this paper for the first time from Korea. The description was based on the observation of living specimens and protargol impregnated specimens. Diagnostic characteristics for each species are as follows. O. balladyna: one micronucleus located between two macronuclei, five transverse cirri, three caudal cirri, five rows of dorsal kinety, no granule in cytoplasm. O. longa: each micronucleus closely located near two macronuclei, three postoral ventral cirri lying in a straight line and positioned far away from transverse cirri, four transverse cirri, two caudal cirri, four rows of dorsal kinety, yellow-green granules scattered on cytoplasm.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.1
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• pp.18-26
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• 2000

Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep damage due to severe operating conditions such as high temperature and high pressure for an extended period time. Conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also these techniques have low practicality and applied only to component surfaces with good accessibility. In this paper, artificial creep degradation test and ultrasonic measurement for their creep degraded specimens(Cr-Mo alloy steels) were carried out for the purpose of evaluation for creep damage. Absolute measuring method of quantitative ultrasonic measurement for material degradation was established, and long term creep degradation tests using life prediction formula were carried out. As a result of ultrasonic tests for crept specimens. we conformed that both the sound velocity decreased and attenuation coefficient linearly increased in proportion to the Increase of creep life fraction($\Phi$c).

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.1
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• pp.38-44
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• 2003

Performance demonstration with real flawed specimens has been strongly required for nondestructive evaluation of safety class components in nuclear power plant. Mechanical or thermal fatigue crack and intergranular stress corrosion cracking could be occured in the in-service nuclear power plant and mechanical fatigue crack was selected to study in this paper. Specimen was designed to produce mechanical fatigue flaw under tensile stress. The number of cycles and the level of stress were controlled to obtain the desired flaw roughness. After the accurate physical measurement of the flaw size and location, fracture surface was seal-welded in place to ensure the designed location and site. The remaining weld groove was then filled by using gas-tungsten are welding(GTAW) and flux-cored arc welding(FCAW). Results of radio graphic and ultrasonic testing showed that fatigue cracks were consistent with the designed size and location in the final specimens.

• Korean Journal of Plant Taxonomy
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• v.46 no.1
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• pp.13-32
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• 2016

Neillieae was traditionally recognized as a small tribe in Rosaceae, which consists of Neillia, Stephanandra, and Physocarpus. Recently, Stephanandra was merged into Neillia based on molecular phylogenetic analyses, meaning that Neillieae now contains Neillia and Physocarpus. The genus Neillia is distinguished from Physocarpus by ovate to lanceolate leaves with acuminate to caudate apices, racemose or paniculate inflorescences, and a unicarpellate (rarely bicarpellate) gynoecium. Plants of Neillia are distributed from the Himalayas across China and Korea to Japan in the east, and south to Indonesia. This study provides a taxonomic treatment of Neillia based on a morphological examination of herbarium specimens, including types, and field observations, as the second part of the taxonomic revision of the tribe Neillieae. A summary of the phylogeny of Neillia, keys to the species, nomenclatural reviews, descriptions, distribution maps, and lists of specimens examined are provided. Twelve species with ten varieties are recognized in Neillia. A lectotype was designated here for the following species: N. sinensis f. glanduligera and N. thyrsiflora.

• Nuclear Engineering and Technology
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• v.42 no.1
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• pp.79-88
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• 2010

Spent $UO_2$ nuclear fuel discharged from a nuclear power plant (NPP) contains fission products, U, Pu, and other actinides. Due to neutron capture by $^{238}U$ in the rim region and a temperature gradient between the center and the rim of a fuel pellet, a considerable increase in the concentration of fission products, Pu, and other actinides are expected in the pellet periphery of high burnup fuel. The characterization of the radial profiles of the various isotopic concentrations is our main concern. For an analysis, spent nuclear fuels originating from the Yeonggwang-2 pressurized water reactor (PWR) were chosen as the test specimens. In this work, the distributions of some actinide isotopes were measured from center to rim of the spent fuel specimens by a radiation shielded laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) system. Sampling was performed along the diameter of the specimen by reducing the sampling intervals from 500 ${\mu}m$ in the center to 100 ${\mu}m$ in the pellet periphery region. It was observed that the isotopic concentration ratios for minor actinides in the center of the specimen remain almost constant and increase near the pellet periphery due to the rim effect apart from the $^{236}U$ to $^{235}U$ ratio, which remains approximately constant. In addition, the distributions of local burnup were derived from the measured isotope ratios by applying the relationship between burnup and isotopic ratio for plutonium and minor actinides calculated by the ORIGEN2 code.

• Journal of Radiation Protection and Research
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• v.11 no.2
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• pp.91-103
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• 1986

Experimental study for the leaching behavior of Cs-137 was carried out using the simulated evaporator bottom product of PWR plant. The method of leach test proposed by the IAEA was partially modified using ANS method. The effect of various factors, i.e., sampling method, curing temperature, curing time, leachant temperature, vermiculite addition and volume-to-surface ratio, was considered in this experiment. Diffusion model in semi-infinite slab was in a good agreement with the data obtained from 4-weeks cured specimens. The effective diffusion coefficient of the specimens which were cured at the temperature of $24^{\circ}C$ for 4 weeks was found to be $1.20{\sim}1.47{\times}10^{-11}cm^2/sec$. With the experimentally obtained diffusion coefficient ($1.47{\times}10^{-11}cm^2/sec$), long-term prediction for the leaching of Cs-137 was carried out using finite-slab approximation. The estimated fraction of Cs-137 which remains in the environment is found to be less than 0.25 percent of initial amount after 100 years. About 25 years after the beginning of leaching, its fractional amount in the environment reachs the maximum value, 0.66 percent of initial amount.

• Korean Journal of Plant Taxonomy
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• v.36 no.1
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• pp.53-59
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• 2006

Here we report a previously unrecorded species of Korean Allium (Alliaceae) from Geomundo, Yeosu-si, Jeollanam-do. This taxon, A. pseudojaponicum Makino which has been known to distribute only in the southern part of Japan up to date, is easily distinguished from A. thunbergii G. don by lustrous evergreen leaves and lateral scapes as well as chromosome number (2n=32). The common name, 'Gaet-bu-chu', was newly given considering the property of habitat, which is the dry and rocky grasslands facing to the sea in Korea and Japan. In this study, we redescribe morphological characters, and provide illustrations of habit as well as photographs of habitat.

• Korean Journal of Plant Taxonomy
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• v.44 no.3
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• pp.165-170
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• 2014

Most evergreen Quercus species are typical, dominant members of Korean evergreen forests. However, little is known about the distribution status of Q. myrsinifolia Blume there. To enhance our knowledge about their natural range in Korea, we conducted field surveys based on specimen records and an extensive literature search. We also determined their exact number as a first step in planning their conservation. The results indicated that these trees are strictly limited to Jin Island, and 169 mature individuals were the maximum number and occurred in only three subpopulations on that island. Previous misidentifications and perhaps mislabeled locations for plant specimens were the main reasons for earlier confusion about distribution. We believe that these results can provide guidance when making specific recommendations for management interventions. These discoveries also demonstrate the value in having reliable information about plant specimens in general. We also speculated about what makes this species particularly vulnerable to local extinction.