• Journal of Soil and Groundwater Environment
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• v.17 no.2
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• pp.15-21
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• 2012

MTBE (Methyl tertiary-butyl ether) has been commonly used as an octane enhancer to replace tetraethyl lead in gasoline, because MTBE increases the efficiency of combustion and decreases the emission of carbon monoxide. However, MTBE has been found in groundwater from the fuel spills and leaks in the UST (Underground Storage Tank). Fenton's oxidation, an advanced oxidation catalyzed with ferrous iron, is successful in removing MTBE in groundwater. However, Fenton's oxidation requires the continuous addition of dissolved $Fe^{2+}$. Zero-valent iron is available as a source of catalytic ferrous iron of MFO (Modified Fenton's Oxidation) and has been studied for use in PRBs (Permeable Reactive Barriers) as a reactive material. Therefore, this study investigated the condition of optimization in MFO-PRBs using waste zero-valent iron (ZVI) with the waste steel scrap to treat MTBE contaminated groundwater. Batch tests were examined to find optimal molar ratio of MTBE : $H_2O_2$ on extent to degradation of MTBE in groundwater at pH 7 with 10% waste ZVI. As the results, the ratio of optimization of MTBE to hydrogen peroxide for MFO was determined to be 1:300[mM]. The column experiment was conducted to know applicability of MFO-PRBs for MTBE remediation in groundwater. As the results of column test, MTBE was removed 87% of the initial concentration during 120days of operational period. Interestingly, MTBE was degraded not only within waste ZVI column but also within sand column. It means the aquifer may affect continuously the MTBE contaminated groundwater after throughout the waste ZVI barrier. The residual products showed acetone, TBF (Tert-butyl formate) and TBA (Tert-butyl acetate) during this test. The results of the present study showed that the recycled materials can be effectively used for not only a source of catalytic ferrous iron but also a reactive material of the MFO-PRBs to remove MTBE in groundwater.

• Journal of Korea Water Resources Association
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• v.41 no.4
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• pp.423-432
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• 2008

The local migration or movement behavior of fishes in streams are related to feeding, spawning, growing, dispersing, and refuging. The pale chub (Zacco platypus) is a dominant species that migrates locally and inhabits in river and stream in Korea. However, dams, weirs, culverts and other regulatory structures are physical barriers that limit fish movement and fragment habits and populations. If main stream and off-channel habitats are connected with culverts, they would restrict the small fish as pale chub movement due to the high flow velocities and low depths. But in Korea, there is no experimental study to evaluate the swimming performance of species in Korea. Therefore, it is difficult to proposed that design guidelines for pass fishes through culverts. The purpose of this experimental study is to evaluate the swimming performance of pale chubs. A series of swimming performance test has been used in both of the fixed velocity and the incremental velocity methods in an experimental flume. As a result, the critical swimming speed for pale chub(body length 8.9 cm) was found to be about 0.7 m/s. Therefore, the flow velocity for culvert design in the low flow condition should not be exceed the its swimming ability, especially 0.7 m/s for pale chubs(body length 8.9 cm). And the minimum depth for culvert design in the low flow condition should not be lower than the fish body height add a dorsal fin height.

• Journal of Environmental Impact Assessment
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• v.25 no.1
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• pp.1-14
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• 2016

With the continuous expansion of highway network and its traffics, neighboring wildlife habitats are splitted into smaller and more isolated patches. The infrastructures contribute to the wildlife-vehicle collision by creating barriers to animal movement. This kinds of traffic accidents are dangerous factors to the drivers' safety and the facilities on the highway as well as to the wildlife themselves. One of the most common ways to prevent habitat fragmentation are fauna crossings and fences. The cost of the mitigation measures to prevent wildlife-vehicle collision could be monetized. However their economic benefits are difficult to be measured. Using contingent valuation method, this study tries to estimate the economic valuation of wildlife collision prevention projects on the Korean highways. The result shows that 43.88% of Korean household had the positive willingness pay to the projects. Moreover, we found that the recognition of the project or the favourable attitude to the environmental issues could raise the willingness-to-pay. Therefore, active public relation on the project could make the friendly public opinion and increase the number of the household which has the positive willingness-to-pay on the project.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.94-106
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• 2008

As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.366-375
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• 2022

The monitoring of electricity consumption using Internet of Things (IoT) technology is attracting attention as a technology to reduce operation costs of smart farms. In this study, we propose a method to apply a real-time electrical consumption monitoring system (the e-Gauge system) and utilization of the collected data real-time while a melon-producing smart farm is in operation. For this purpose, the electrical consumption data for the individual smart-farm facilities such as boilers, nutrient distribution systems, automatic controllers, circulation fans, boiler controllers, and other IoT-related utilities were collected during three months of melon cultivation period. By using the monitoring results, the electrical energy consumption pattern was analyzed as an example, and necessary considerations needed to optimally utilize the measurement data were suggested. This paper will be useful in lowering the technological implementation barriers for new researchers to build a electrical consumption monitoring system and reducing trial and errors in the usage of the generated data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2244-2255
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• 2014

This study aimed to compare smoking, drinking, dietary management, personal hygiene, and oral care between immigrant women in urban and rural areas and to determine predictors of the overall health behaviors. With the standardized questionnaire used for community health survey data collection was performed in 128 immigrant women from November 2011 to October 2012. Rural women performed significantly higher numbers of health behaviors than urban women and residential district, education, employment status, and perceived difficulties related to cultural adaptation significantly predicted health behaviors in immigrant women. Immigrant women in urban areas may be highly vulnerable in maintaining health behaviors compared with rural women and cultural barriers may hinder positive health behavior maintenance. Therefore, careful considerations at individual, community, and environmental levels are needed when assessing immigrant women's health behaviors and designing culturally relevant interventions to improve health status.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.377-385
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• 2014

This study is aimed to introduce the newly developed mobile application for effective provision of assistive devices for people with disabilities in South Korea. By combining of ICF code and ISO 9999 code, more effective way of searching user fit assistive device information and selecting appropriate assistive devices were possible. 10 people with visual impairment were recruited for an usability testing. For the data analysis, paired t-test were used and confidence interval was 95%. The result showed newly developed mobile application was more effective in comparison with on-line based assistive device information. The outcome of this study will enhance the provision of assistive devices for people with disabilities more effectively within better user understanding of their needs and compensate for their body function as well as environmental barriers.

• International Commerce and Information Review
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• v.11 no.4
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• pp.395-418
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• 2009

Appeared in the 1970s he started the global warming problem of carbon reduction, unlike the expected withdrawal of the United States was anticipated to be nominal stripping. However, EU mainly carbon market, buy and sell rights to be disposed of evolution was born. In fact, the current reduction of the Kyoto Protocol, and Korea will be designated as the bureau had been scheduled. However, due to economic recession in Korea's status as exempt countries have enjoyed a considerable period. Global warming is a problem in earnest, however, the United States to participate in one or more such discussions since 2013, clearly this will begin the international order. And international order that is more stringent than expected, and is expected to be strong. Then, however, an interesting thing to justify protection of the environment in some countries to protect domestic industry, the movement is visible is the side. In fact the WTO since the conclusion of all non-tariff trade barriers were abolished. However, recently, New Round of the delay based on reciprocity and fair trade in the framework of environmental protection to justify the movement to protect the domestic industry has been captured. These trends are not friendly, never in Korea. The rationale is that these regulations are enforced, many of our countries and countries with significant trade transactions and the enforcement points. And South Korea's automotive, semiconductors, ships, etc. The main products are much discussed in the international regulations are being referred to as the target point is due. Korean government to actively participate in the international situation and efforts to explore new markets, said yesterday, and 'Low Carbon, Green Growth' was declared. And the Intergovernmental Panel on Climate Change(IPCC) recommendations of the best 30% reduction target was present. This is nothing different about this objection is true. A more fundamental solution to faithfully perform the reduction targets, while the development of environmentally friendly products and the incidence of international standards through the development and expansion of new growth engines, Indeed we are expected to be a fundamental methodology.

• The KSFM Journal of Fluid Machinery
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• v.16 no.1
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• pp.56-60
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• 2013

Non-conventional oil resources such as shale gas are becoming increasingly important and have drawn the attention of several major oil companies all over the world. Nevertheless, the market-changing growth of shale gas production in recent years has resulted in the emergence of environmental and water management challenges. This is because the water used in the hydraulic fracturing process contains large amount of pollutants including ions, organics, and particles. Accordingly, the treatment of this flowback water from shale gas plant is regarded as one of the key technologies. In this study, we examined the feasibility of membrane distillation as a treatment technology for the water from shale gas plants. Direct contact membrane distillation (DCMD) is a thermally-driven process based on a vaper pressure gradient across a hydrophobic membrane, allowing the treatment of feed waters containing high concentration of ions. Experiments were carried out put in the lab-scale under various conditions such as membrane types, temperature difference, flow rate and so on. Synthetic feed water was prepared and used based on the data from literature. The results indicated that DCMD is suitable for treating not only low-range flowback water but also high-range flowback water. Based on the theoretical calculation, DCMD could have over 80% of recovery. Nevertheless, organic pollutants such as oil and surfactant were identified as serious barriers for the application of MD. Further works will be required to develop the optimum pretreatment for this MD process.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.85-91
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• 2012

Permeable Reactive Barriers (PRBs) using zero valent iron (ZVI, $Fe^0$) is a promising technology for in-situ remediation of trichloroethylene (TCE) forming dense non aqueous phase liquid (DNAPL). The objective of this study is to develop an enhanced treatment method of trichloroethylene-contaminated groundwater using ZVI packed bed with direct current (D.C.). A column experiment was performed to investigate degradation efficiency of TCE that was performed in three different combination of control (only sand), ZVI column (ZVI:sand, packing ratio 1:2(v/v)) and bipolar column (ZVI:sand=1:2(v/v) with electric current) in the test columns. As the results of this study, the degradation efficiency of TCE was improved with simultaneous application of both bipolar column compared to that used ZVI column. Because ZVI particles are isolated and individual particles act like small electrodes. In this experiment, it was indicated a basic material for application of bipolar packed bed as electro-PRBs that was effective degradation of TCE.