• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.445-455
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• 2003

Relatively high carbon-14 emissions, which occurred at PHWR Plant during 1998 and 1999, made the site staff to implement several operational improvements: 1) the frequency and volume of the moderator cover gas purging were reduced through increased $O_2$ additions to the cover gas, 2) the 'old' resin columns were not used during re-start of the reactor from outage, 3) efforts were made to minimize air ingress, 4) the maximum service time of moderator ion-exchange columns were restricted to about 80 days. Through the improvements, the carbon-14 emission from each PHWR reactor returned to the normal levels during the remainder of 1999 and during 2000. We carried out a special surveillance at W-1 and W-3 from September 2001 to August 2002 to properly evaluate ways to optimize the use of moderator ion exchange resins from a C-14 perspective. The surveillance showed that only data that provided an operational marker for deciding when to remove the IX-resin column is an observed increase in the C-14 stack emissions themselves. Also, it is shown that any increase over the rate of 0.4 Ci $month^{-1}$ for two consecutive weeks may be the indication for an ion-exchange resin column change, especially if the IX-resin column has been in service for more than 80 days.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.47-55
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• 2011

Cicada is a very familiar insect to people but habitat characteristics of them are not well known. To investigate habitat characteristics of cicada nymph, plant species, plant cover, soil hardness, accumulated organic mass, organic content in soil, and root density were investigated at 11 sites in an apartment complex garden in Seoul. Selected sites had different densities of cicada nymph case above the ground. Density of cicada nymph case was positively correlated with accumulated organic mass, organic content in soil, and root density and negatively correlated with soil hardness. Even though shrub coverage was not linearly correlated with the density of cicada nymph case, 80% cover of shrub was necessary for the high density of them. Data in this study suggested that organic matter in addition to root density be the primary limitation factor of cicada nymph and high amount of litter-fall decrease soil hardness through the increase of soil organic matter. This study suggests that the density of cicada nymph can be managed through organic content in soil.

• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.160-165
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• 2014

The realistic cases causing severe core damage should be analyzed and arranged systematically for preparing an accident management of the specific nuclear power plant. The objective of this paper is to establish basic technical information for reactor safety and reactor building integrity management strategies in CANDU reactor severe accident. For the development of severe accident management strategies, plant specific features and behaviors must be studied by detailed analysis works. This analysis scope will serve to cover overall methods and analyzing results to understand the reactor building integrity status in the most likely severe accident sequences that could occur at CANDU reactor. Also analysis results could help prevent or mitigate severe accidents for the identification of any plant specific vulnerabilities to severe accidents using the probabilistic safety assessment (PSA) quantified results.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.367-373
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• 2000

We have constructed a molecular linkage map of chili pepper (Capsicum spp.) in an interspecific (C. annuum cv. TF68 x C. chinense cv. Habanero) F$_2$ population of 107 plants with 150 RFLP and 430 AFLP markers. The resulting linkage map consists of 11 large (206-60.3 cM) and 5 small (32.6- 10.3 cM) linkage groups cover-ing 1,320 cM with an average map distance between framework markers of 7.5 cM. Most (80%) of the RFLP markers were pepper-derived clones and these markers were evenly distributed across the genome. By using 30 primer combinations, 444 AFLP markers were generated in the F$_2$population. The majority of the AFLP markers clustered in each linkage group, although PstI/MseI markers were more evenly distributed than Eco RI/MseI markers within the linkage groups. Genes for biosynthesis of carotenoids and capsaicinoids were mapped on our linkage map. This map will provide the basis of studying secondary metabolites in pepper.

• Korean journal of applied entomology
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• v.8
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• pp.25-28
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• 1969

In order to find out the effect of contactor to form appressorial structure of Glomerella glycines, this experiment was carried out by using several contactors such as cover glass. cellophane, vinyl and oil paper respectively. In the case of cover glass placed on a drop of conidial suspension of the fungus which is incubated on water agar for 12 hours, 67.7 percent of appressoria were resulted, whereas no appressorial structure was found in the control. Vinyl was known best physical contactor and cellophane, cover glass and oil paper were fairly good in that order. Effects of temperature, time and relative humidity on the formation of appressoria of G. glycines were similar to each of optimum growth range of temperature and relative humidity $25^{\circ}-30^{\circ}C$ and 70-100 Percent, respectively. In addition, maximum appressorial formation was resulted in the conidial suspension incubated on soybean leaves for 36 hours. No appressorium was found at above $35^{\circ}C$, below R.H. 70 percent and 5 hours incubation.

• Forest Science and Technology
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• v.14 no.4
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• pp.181-191
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• 2018

This study was carried out in the teaching and research forest of the University of Dschang in Belabo, with the aim of analysing land-cover and land-use changes as well as carbon stocks dynamic. The databases used are composed of three Landsat satellite images (5TM of 1984, 7ETM + of 2000 and 8OLI of 2016), enhanced by field missions. Satellite images were processed using ENVI and ArcGIS software. Interview, focus group discussion methods and participatory mapping were used to identify the activities carried out by the local population. An inventory design consisting of four transects was used to measure dendrometric parameters and to identify land-use types. An estimation of carbon stocks in aboveground and underground woody biomass was made using allometric models based on non-destructive method. Dynamic of land-cover showed that the average annual rate of deforestation is 0.48%. The main activities at the base of this change are agriculture, house built-up and logging. Seven types of land-use were identified; adult secondary forests (64.10%), young secondary forests (7.54%), wetlands (7.39%), fallows (3.63%), savannahs (9.59%), cocoa farms (4.28%) and mixed crop farms (3.47%). Adult secondary forests had the highest amount of carbon ($250.75\;t\;C\;ha^{-1}$). This value has decreased by more than 60% for mixed crop farms ($94.67\;t\;C\;ha^{-1}$), showing the impact of agricultural activities on both forest cover and carbon stocks. Agroforestry systems that allow conservation and introduction of woody species should be encouraged as part of a participatory management strategy of this forest.

• Research in Plant Disease
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• v.26 no.2
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• pp.116-119
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• 2020

To investigate the effects of Brassicaceae cover crops on clover cyst nematode, Heterodera trifolii, 10 cultivars consisting of six of oil radish and four of white mustard were planted in the nematode infected field at Jeongseon city. Two months after planting, the cover crops were plow down and incorporated into the soil using rotavator, decomposed for 1 month, then transplanted kimchi-cabbages. After 70 days, the density of eggs inside of the cyst and the number of females in the soil were examined. As a result, the reproduction rates of eggs in each plots of Adios and Anaconda cultivars, which were 0.04 and 0.02, respectively, were greatly reduced. The number of females in the plots of above two cultivars showed means at 2.5 and 3.5 per 300 ㎤ soil, which were lower than those of other plots. In addition, fresh weights of three plants in the two plots, which were 7.67 and 7.35 kg, were significantly higher than that of the control plot. Collectively, these results suggest that the two cultivars of Brassicaceae cover crops, Adios and Anaconda, could be used for reducing the cyst nematode density.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.48-48
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• 2017

The objectives of this study were to determine the dominance frequency of plant species between spring and summer, to provide useful information toward the conservation to increasing production cattle feed in grazing area in Hiroshima, Japan. The frequency of dominant plant species can adapt in the spring and summer, that consist of Paspalum dilatatum (spring 69.32% and summer 78.98%), Paspalum notatum (spring 47.73% and summer 98.30%), Trifolium repens (spring 73.86% and summer 81.25%). The observed plant species also influenced some productivity, which consists of plant height (spring 16.64 cm and summer 21.55 cm), vegetation cover rates (spring 77.18% and summer 81.36%, chlorophyll content (spring 41.72 mg/g Fw and summer 36.28 mg/g Fw), diversity index (spring 0.94 and summer 0.80), evenness index (spring 0.93 and summer 0.67), and species numbers (spring 32.0 and summer 21.0). It is proposed that Paspalum dilatatum, Paspalum notatum, and Trifolium repens, can be used to increase productivity of plant species as cattle feeds.

• Korean Journal of Plant Resources
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• v.25 no.5
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• pp.652-655
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• 2012

'Blue Edge' (Hosta minor) was induced by ethyle methane sulfonate (EMS) to obtain mutants. Among induced leaf variegated hosta plants, some with deep-green color pattern on the edge of the leaves was selected. They were cultivated via vegetative propagation. Assessment of botanical characteristics was conducted for three years since 2003. The major characteristic of these cultivars is that they maintain their deep-green color on the edge of the leaves all year round. These cultivars are useful as materials for pot plant or as ground cover plant.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.256-263
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• 2020

Background: Ambrosia trifida is a highly invasive annual plant, but effective control methods have not been proposed. Among various eradication methods, cutting is a simple measure to control invasive plants, and sowing seeds of native plants may effectively increase biotic resistance to invasion. In this study, we conducted a field experiment with two treatments: cutting and sowing seeds of six native or naturalized plants. Results: We found a significantly lower A. trifida abundance after cutting than in the control (77% decrease). Sowing seeds of native species did not provide any additional benefit for the control of A. trifida, but increased the importance values and diversity of other native vegetation. The abundance of A. trifida was negatively correlated with that of other plant taxa based on plant cover, biomass, and density. However, biotic resistance of sown plants was not effective to control invasion because A. trifida was so competitive. Conclusions: We concluded that cutting is an effective measure to control Ambrosia trifida while sowing seeds of native plants can increase native plant diversity.