• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.81-90
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• 2010

In this study, primary investigation for evaluation of abandoned metal mine effect on watershed has been done. 64 abandoned mines have been selected for primary investigation through literature and field survey. 216 soil and 90 water samples were collected and metal pollution concentrations were analyzed. 24 mines have mine water in the pits and acid water below pH 5 was not observed. Soils from 35 mines were over the soil basis of concern and 16 mines were over the soil basis of action. Arsenic average concentration was 188 times of average concentration of the natural background. Drinking water samples from 3 mines were over the drinking water standard and surface water samples from 12 mines were over the river water standard. Integrated pollution index, which was resulted from the integration of field survey, soil and water pollution concentration, showed that, abandoned metal mines had affected on watershed greatly in the order of Samgeum, Daedeok, Cheongdalgeum, Heungsin, Yeongdae and Myeongbong mines.

• Composites Research
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• v.27 no.1
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• pp.19-24
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• 2014

In this study, an investigation on mechanical properties of flax/vinyl ester natural fiber composite was performed as a precedent study on the design of eco-friendly structure using flax/vinyl ester composite. Vacuum Assisted Resin Transfer Molding(VARTM) manufacturing method was adopted for manufacturing the flax fiber composite specimen. The mechanical properties of the manufactured flax composites were compared with flax composite data cited from some references. Based on this, the experimental data showed that the flax/vinyl ester composite has some advantages when it is applied to environment-friendly structure.

• Korean Journal of Environment and Ecology
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• v.24 no.2
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• pp.130-138
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• 2010

The purpose of this study is the investigation and analysis of information on the conservation and the sustainable use of coastal wetlands based on the awareness of local residents in Suncheon Bay and Taeanhaean National Park. To accomplish the purpose of study, a questionnaire survey was chosen and the 98 valid samples(38 from Taeanhaean National Park and 60 from Suncheon Bay) among them were analyzed. The results are summarized as follows: The degree of the satisfaction on the natural environment is alike between Taeanhaean National Park and Suncheon-bay area. This is accorded with the order of the goodness of natural environment. The order for the degree of the satisfaction on the living environment is same as the order for the satisfaction degree on the natural environment. The residents of two regions are not satisfied with the socio·economic environment. The local resident of Suncheon Bay and Taeanhaean National Park Area where natural environment is well-conserved, prefer conservation to development of the region. These results show the following consideration for the ideal method of management for the conservation and sustainable development of coastal wetlands. In case of Suncheon Bay area, where the condition the natural environment is well conserved, should be managed with the minimum development with maintenance of the current state must be driven. In case of Taeanhaean National Park Area, where the condition of the natural environment is well conserved and the development potential exists, such as sustainable development and ecotourism destination the development that is in harmony with the nature must to be driven.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.185-199
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• 2012

Ecotourism has been attracting much attention as an example industry that can vitalize local economy markets and preserve natural resources. Implementation of 'Ecotourism Designation System' is under consideration to provide ecotourism products that can both emphasize the original meanings of ecotourism and ensure stronger trust from customers than ever before. This research introduced the direction, principles, subjects, and assessment indicators by subjects in terms of implementing the system and proposed fundamentals for both designation assignment and score calculation. In the face of implementing such a system in Korea, the investigation sought subjects whose target areas and programs are in need of examination. For assessment criteria by subjects, six assessment indicators were selected in the end for ecotourism sites, including: (1) the value of natural/ecological preservation (2) facility's ecological design (3) understanding both the environment and local culture (4) systems connecting local communities for cooperation (5) long/short term preservation and maintenance strategies/plans (6) willingness to further develop ecotourism and cooperative platform. In addition, seven assessment indicators were selected for program assignments, including: (1) the value of natural/ecological preservation (2) minimization of environmental effects (3) expansion of environmental understanding (4) sharing the local culture (5) vitalizing local connections and economical activities among communities (6) securing and maintaining professionality among human resources (7) odds of continuation, creativity, and aptness to improve programs. After considering the pros and cons of both categorizing system and yes/no system, implementation of categorizing system for the short term and yes/no for the long term were suggested, followed by additional suggestions of a score calculation system for each system. The official implementation of the 'Ecotourism Designation System' is scheduled for launch in 2013 after the trial operation in 2012. The assessment indicators and fundamentals suggested in this research, considering judgment, must be improved via systematic and practical methods through the trial operation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.922-924
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• 2014

This paper is concerned with the analysis of natural vibration characteristics of an accelerometer used in power plant. The malfunction of the accelerometer in high-temperature environment may produce erroneous sensor signal and the erroneous signal may cause unpredicted accidents in power plants. Hence, the accelerometer which endures high temperature needs to be developed. In this study, the natural vibration characteristics of the accelerometer were investigated prior to the development of the high-temperature accelerometer. The main mechanical part of the accelerometer is a spiral spring. In this study, the dynamic characteristics of the spiral spring were investigated first by using a commercial finite element code. Numerical results show that the thickness of the spiral spring affects the dynamic characteristics. Numerical investigation on the effect of temperature on the performance of the accelerometer will follow.

• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.6-14
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• 2019

There are about 38,977 CNG cars and 247 natural gas vehicle charging stations in operation in order to improve the urban air environment. With the introduction of natural gas vehicles, the atmospheric environment, which was the main cause of air pollution in the metropolitan area, was remarkably improved. However, unlike these positive effects, CNG bus accidents, which occurred more than 10 times since 2005, have caused concern among the majority of citizens using public transportation. It is necessary to make a judgment on the feasibility and future direction of CNG pressure vessel safety management that can safeguard the safety of CNG pressure vessel at the time of starting. In this study, we investigates production and use of CNG vessel, the current status of safety management of CNG bus transportation companies & charging stations and then proposes measures to prevent accident recurrence and safety management based on the actual situation investigation and analysis.

• The Journal of Sustainable Design and Educational Environment Research
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• v.7 no.1
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• pp.39-55
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• 2008

The purpose of this study is to suggest improvement of certification standards of environment friendly architecture in ecological environment field by surveying and analyzing actual status of actual certification schools of environment friendly architecture per ecological environment elements through extracting ecological environment elements which is possible to analyze in quantity certification standards of environment friendly architecture. As contents of the study, first, certification as an examination on certification system of environment friendly architecture, summary of certification system of environment friendly architecture, ecological environment elements which is possible for quantitative analysis of ecological environment certification standards were extracted. Second, actual status of ecological environment elements per school grade, region, and population increase by collecting actual data of certification schools of environment friendly architecture. Third, using analysis data of ecological environment elements, ecological area ratio of certification schools of environment friendly architecture per weighted values of space types was calculated and the results were analyzed as the follows. (1) In case of preliminary certification out of total objects of investigation schools was average 34.06% but in this case of certification, it was reduced to 33.07%. However, it is difficult to make judgment as actual evidence data since ecological area ratio of actual preliminary certification is data based on drawing planes. Therefore, in case of this certification, elementary schools was investigated at average 33.11%, middle schools 34.81%, and high schools 31.28% and middle school showed the highest relatively. (2) Besides, average composition ratio of ecological area ratio was 63.04% in case of this certification regardless of school grade and region and it was analyzed that about 70% of ecological area ratio is composed of the natural based green area including pure natural based green land and 6.89% of ecological learning institute.

• Korean Journal of Ecology and Environment
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• v.44 no.4
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• pp.358-363
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• 2011

This study investigated the characteristics of natural organic matter(NOM) with tXAD resin and FT-IR in the Yeongsan river system of Gwangju region. NOM fractionation by XAD 8/4 resins was used to classify hydrophobic and hydrophilic substances. FTIR was applied to classify functional groups in the structure of NOM. In the XAD investigation, most of the four site-samples were mainly hydrophilic substances. In March, hydrophobic substances were dominant in the Gwangju 1 site (GJ-1), while hydrophilic substances were dominant for the other sites. In May, samples of all four sites were hydrophilic with a vigorous activity of microorganism due to increasing temperatures. The October results were very similar with those from March. In the FT-IR investigation, most of the broad and large peaks were assigned to the aliphatic group, particularly the OH group, C-H, $C-H_2$, $C-H_3$, and C-O alcohol group. All were related to hydrophilic substances. Other peaks showed the aromatic group, particularly the C=O (Ketone) Group. As a result, there is an identification of NOM in the Yeongsan river system composing mainly of hydrophilic substances and functional groups (OH, C-H etc.) of the aliphatic compound.

• Textile Coloration and Finishing
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• v.21 no.6
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• pp.29-38
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• 2009

Natural dyes seem to be more profitable on human and environment, and recently they could be considered as a better alternative to synthesized dyes. The aim of the current work was to investigate the dyeing property and antimicrobial activity of commercial cotton fabrics dyed with kumazasa (usually called in japan) which is known as conventional japan bamboo leaves. Actually, the dyeability and antimicrobial property of dyed fabric with natural mordant/dyeing was compared with synthetic mordant/dye process. The results of this study obtained are as follows. The apparently colour of kumazasa leaves extract dyed fabrics showed with light green or slightly yellow-green. In colorfastness to washing, ${\Delta}E$ and K/S values of dyed fabrics with natural chitosan as mordant used was shown to be more excellent results, than was synthetic mordant used. However, the decrease rate was recorded nearly 50% when washing repeated 20 cycles. In result of antimicrobial effect for bacteria, the dyed fabrics didn't show the significant antimicrobial activity to the both dyed with and without mordant. Results of this investigation considered that low-cost, natural, bio-mordant are relatively effective in natural coloration.

• International Journal of Air-Conditioning and Refrigeration
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• v.15 no.1
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• pp.25-33
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• 2007

The investigation has been made into the prediction of heat exchange performance of a counter flow type double-tube condenser for natural refrigerant mixtures composed of Propane/n-Butane or Propane/i-Butane in a smooth tube and micro-fin tube. Under various heat transfer conditions, mass flux, pressure drop and heat transfer coefficient of the mixed refrigerants were calculated using a prediction method, when the length of condensing tube, total heat transfer rate, mass flux and outlet temperature of coolant were maintained constant. Also, the predicted results were compared with those of HCFC22. The results showed that the mixed refrigerants of Propane/n-Butane or Propane/i-Butane could be substituted for HCFC22, while the pressure drop and overall heat transfer coefficient of the refrigerants were evaluated together.