• Journal of the Korean institute of surface engineering
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• v.49 no.2
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• pp.159-165
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• 2016

The hydrogen has been recognized as a clean, nonpolluting and unlimited energy source that can solve fossil fuel depletion and environmental pollution problems at the same time. Water electrolysis has been the most attractive technology in a way to produce hydrogen because it does not emit any pollutants compared to other method such as natural gas steam reforming and coal gasification etc. In order to improve efficiency and durability of the water electrolysis, comprehensive studies for highly active and stable electrocatalysts have been performed. The platinum group metal (PGM; Pt, Ru, Pd, Rh, etc.) electrocatalysts indicated a higher activity and stability compared with other transition metals in harsh condition such as acid solution. It is necessary to develop inexpensive non-noble metal catalysts such as transition metal oxides because the PGM catalysts is expensive materials with insufficient it's reserves. The optimization of operating parameter and the components is also important factor to develop an efficient water electrolysis cell. In this study, we optimized the operating parameter and components such as the type of AEM and density of gas diffusion layer (GDL) and the temperature/concentration of the electrolyte solution for the anion exchange membrane water electrolysis cell (AEMWEC) with the transition metal oxide alloy anode and cathode electrocatalysts. The maximum current density was $345.8mA/cm^2$ with parameter and component optimization.

• Korean Institute of Interior Design Journal
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• v.17 no.3
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• pp.111-122
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• 2008

As Korea has undergone rapid modernization, urbanization and industrialization, women's social participation has increased. Accordingly, child care facilities have shown continuous growth in numbers. However, according to research, child care facilities in Korea lag behind those in other nations in terms of quality. Given that, it seem urgent to enhance the quality of child care facilities and improve their indoor environment. Above all, overall atmosphere, colors and finishing materials are connected directly with educational effects as well as feelings and health of facility users. This study assesses the current state of child care facilities and preferences by focusing primarily on interior atmosphere, materials and colors. For This Study, 7 facilities were surveyed, and 46 subjects were participated for this study. The findings suggest that "pretty" style is preferred to "natural" style. As regards flooring material, wood floor is preferred. It is recommended to lay pastel colored carpet or PVC flooring material to the wood floor. As for wall, it is desirable to divide the wall spaces by adding wood and painting to simple wallpapers. In case of the ceiling noise absorptive material is recommended to use instead of wallpapers. For the doors, it is desirable to use contrasting materials and colors given accessibility for children. In the meantime, rather than strong primary colors, soft color or pastel colors are desirable for furniture. This study has limitations because of insufficiency of case study samples. However, it is significant in that the study results may be used as primary source of information to improve the environment of child care facilities.

• The Korean Journal of Mycology
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• v.45 no.1
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• pp.1-13
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• 2017

Armillaria species are non-obligate root pathogens, as well as facultative parasites. The genus consists of about 40 species with worldwide distribution that are difficult to identify morphologically. Their hosts include conifers, hardwoods, vines, and even herbs. These fungi contribute to natural thinning and succession of vegetation in forests and decompose wood to develop edible fruiting bodies from spring to autumn. Its genets have a lifespan of up to 2000 years and have been found to occupy as much as 960 ha of forest land. Recently, forest tending work such as thinning of forests has resulted in the creation of tree stumps that support the growth of Armillaria, and these mushrooms have become an income source in mountainous areas. Therefore, identification of these species is needed. We review the difficulties in identification, suggest a species identification key for Korean indigenous species, and discuss the significance of Armillaria in terms of forest ecology and plant pathology.

• Mycobiology
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• v.48 no.5
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• pp.427-430
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• 2020

Ganoderma lingzhi is a well-known source of natural fungal medicines which has been given for the treatment of several diseases. China is one of the major commercial producers of Ganoderma mushroom worldwide. However, with the expansion of the commercial cultivation, the occurrence of the fungal diseases on G. lingzhi has also been increased. The green mold disease symptoms were observed in the cultivation base of G. lingzhi in Zuojia Town, Jilin City, Jilin Province, China, causing the basidiomes to be rotten and withered, and the green mycelium layer generated gradually. The pathogenicity tests showed the same symptoms as appeared naturally in Zuojia mushroom base. Morphology characters revealed conidia green, ellipsoid, globose, 2.56-4.83 × 2.09-4.22 ㎛, length-width ratio was 1.1-1.2 (n = 10). Conidiophores trichoderma-like, often asymmetry, branches solitary, paired or in whorls of 3 phialides formed solitary, paired or in whorl, variable in shape, lageniform, sometimes ampulliform or subulate. While using molecular methodology, comparing with the sequences of Trichoderma hengshanicum from GenBank, the analyzed sequence showed 97.32% homology with the RPB2 sequences, 100% with the TEF1-a sequences. A fungus isolated from the diseased tissues was identified based on morphology and molecular studies as T. hengshanicum. This is the first report of T. hengshanicum causing the green mold disease of G. lingzhi in China.

• Nuclear Engineering and Technology
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• v.36 no.2
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• pp.196-202
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• 2004

KAERI (Korea Atomic Energy Research Institute) is at present preparing a preliminary performance assessment to set up the HLW disposal concept of Korea. The solubility of the radionuclides contained in HLW is necessary as a source term in order to predict their potential migration in both the near and far fields. The solubility of actinides (Th, Am, U, Np and Pu) for a reference deep groundwater of Korea has been calculated using a geochemical code with thermodynamic data selected by a peer review of existing thermodynamic databases and literature. The solubilities from the experimental study and/or field observations from natural analogue studies are compared. The sensitivity of solubility to the variability of three main parameters of groundwater (pH, Eh, and carbonate concentration) is also investigated. The results of the sensitivity analysis show that the solubility of actinides strongly depends on the parameters considered. Within the range of parameter values studied (pH=7 to 10, Eh=-0.4 to -0.1V, and carbonate concentration=1.E-5 to 1.E-2 mol/L), the solubility of each actinide exists between 1.4E-10 and 1.6E-6 mol/L for Am, 4.9E-9 and 2.8E-6 mol/L for Th, 3.2E-9 and 5.7E-4 mol/L for U, 1.1E-9 and 1.0E-7 mol/L for Np, and 4.0E-11 and 2.8E-6 mol/L for Pu, respectively.

• Hwankyungkyoyuk
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• v.21 no.2
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• pp.51-67
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• 2008

The purpose of this study is to develop and applicate the elementary environmental textbook in order to solve its problem and to improve attitude related to the Asian dust. The results in this research are as follows. First, it was showed that three groups who composed of teachers, parents and students in the elementary school had recognized the serosities and problems caused by the Asian dust form TV, and that such problems was associated with increase of the desertification and the global warming. Especially the student group insist that the cause in Asian dust is due to the natural phenomena or industrialization. Second, as a result in analysis on the Asian dust through both textbooks on the 7th elementary curriculum and subsidiary textbooks, contents concerning Asian dusts was little or noting. In addition, in the subjects of Science, Society and Health for the 5th and 6th grade students in the elementary school, they were explained partially as one of the air pollutants. Third, the elementary environmental textbook on the Asian dust was developed for the 5th and 6th grade students. The textbook is composed of four contents on the material which is harmful of the human health and life in Asian dust, the special news of Asian dust, and the best answer to solve Asian dust as well as the cause and the source of Asian dust. Forth, as a result in classes using the environmental textbook developed by four themes about the Asian dust, its application is meaningful in the level of p value in the view of knowledge, awareness and attitude of the experiment group. They was more improved in 37%, 14%, and 15%, respectively, than the comparative group. In conclusion, the environmental textbook related to Asian dust will play an important role in useful tool to understand the right knowledge, awareness, and attitude which makes an effort on its effective management in the elementary school.

• Research in Plant Disease
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• v.11 no.1
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• pp.16-20
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• 2005

Several time-course experiments were carried out to understand seasonal development of melanose on yuzu trees at koehung area, Jeonnam province, during May to October. The occurrence of dead twigs, known as a source of infection, was much more in older trees, and from June to August, mostly in July. In the experiment of pycnidia development on dead twigs seasonally collected, the number of developed pycnidia was highest on July-collected dead twigs especially with the diameter of 1.1~1.5 cm. In the collection survey of disseminated pycnidiospores, although the collected number of pycnidiospores was affected with amount of precipitation, the number of observed pycnidiospores in rainwater was relatively high from June to August, with highest in early August in 1997 and late July in 1998. In the inoculation tests on 3-year-old trees and fruits in natural condition, disease occurrences were mostly affected on twigs by inocula treatment in June, and on fruits by inocula treatment in July, respectively.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.1-10
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• 2007

This study was reviewed on the bioethanol production from biomass resources and feedstock supply in America. U.S. Department of Energy (USDE) and the u.s. Department of Agriculture USDA) are both strongly committed to expand the role of biomass as an energy source. They support biomass fuels and products as a way to reduce the need for oil and gas imports, to strengthen the nation's energy security and environmental quality. And it was envisioned a 20 percent replacement of the current U.S.transportation fuel consumption in 2030. Also it was reviewed policies to encourage the expanding of Bio-based fuel use to replace gasoline, such as Clean Air Act, Federal Clean Fuel Program and American Jobs Creation Act. In feedstock supply it was assumed forest biomass will be supplied in 368 million dry tons yearly and the agriculture derived biomass adopted by new technologies and land use change will be supplied in 998 million dry tons, including highly 818 million dry tons of lignocellulosic biomass such as perenial crops (hybrid trees, grasses) corn stover, other crop residues. This amount is 5 times to the amount from based current agricultural technology and crop land.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.20-25
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• 2012

New Zealand suffers from regular floods, these being the most common source of insurance claims for damage from natural hazard events in the country. This paper describes the origin and distribution of the largest floods in New Zealand, and describes the systems used to monitor and predict floods. In New Zealand, broad-scale heavy rainfall (and flooding), is the result of warm moist air flowing out from the tropics into the mid-latitudes. There is no monsoon in New Zealand. The terrain has a substantial influence on the distribution of rainfall, with the largest annual totals occurring near the South Island's Southern Alps, the highest mountains in the country. The orographic effect here is extreme, with 3km of elevation gained over a 20km distance from the coast. Across New Zealand, short duration high intensity rainfall from thunderstorms also causes flooding in urban areas and small catchments. Forecasts of severe weather are provided by the New Zealand MetService, a Government owned company. MetService uses global weather models and a number of limited-area weather models to provide warnings and data streams of predicted rainfall to local Councils. Flood monitoring, prediction and warning are carried out by 16 local Councils. All Councils collect their own rainfall and river flow data, and a variety of prediction methods are utilized. These range from experienced staff making intuitive decisions based on previous effects of heavy rain, to hydrological models linked to outputs from MetService weather prediction models. No operational hydrological models are linked to weather radar in New Zealand. Councils provide warnings to Civil Defence Emergency Management, and also directly to farmers and other occupiers of flood prone areas. Warnings are distributed by email, text message and automated voice systems. A nation-wide hydrological model is also operated by NIWA, a Government-owned research institute. It is linked to a single high resolution weather model which runs on a super computer. The NIWA model does not provide public forecasts. The rivers with the greatest flood flows are shown, and these are ranked in terms of peak specific discharge. It can be seen that of the largest floods occur on the West Coast of the South Island, and the greatest flows per unit area are also found in this location.

• Korean Journal of Medicinal Crop Science
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• v.15 no.1
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• pp.56-61
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• 2007

This study was carried out to determine the antioxidant activity and vitamin C contents in plant extracts of the Momordica charantia L. The vitamin C was detected as the highest content in immature fruit (92.2 mg/100 g), while the content in stem (2.5 mg/100 g) was lower 40 times than that of immature fruit. Antioxidant activity for the dried sample was investigated by TBA method. The lowest TBARS values were obtained from extracts of dried leaf and followed by ascorbic acid and BHT, showing that the extracts from dried leaf possess the strongest antioxidant activity. Compared with fresh tissues, SOD activity, ATX activity and CAT activity were high level in the dried tissue. These results suggest that the Momordica charantia L. would be a promising antioxidant source as an alternative antioxidant, based on natural plant resources.