• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.533-536
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• 2008

Korean water quality guidelines for agricultural were derived to protect agricultural water uses according to the Canadian methodology. The adverse effect of heavy metals in agricultural water was of concern due to its persistence, bioaccumulation and ecotoxicity to crop plants. The ecotoxicity data of cadmium, copper, lead, and zinc were collected for the crops grown in Korea, and used to estimate the species maximum acceptable toxicant concentration (SMATC), which corresponds to the water quality guideline. Values of irrigation per year and soil bulk density were revised to reflect the Korean situation. The estimated guideline values for cadmium, copper, lead, and zinc were 0.01, 0.5, 0.1, and 1.0 mg/L, respectively. These values are in agreement with the agricultural water quality guidelines of foreign countries and current Korean water quality standard for the protection of public health. Current water quality standards in agricultural uses were for management of public water resource, and was not prepared to protect crop plants from contaminants. The results of this study will be a basis for the designation of Korean water quality guidelines for the protection of agricultural water uses in the future.

• Journal of environmental and Sanitary engineering
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• v.4 no.2 s.7
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• pp.91-99
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• 1989

An anaerobic acidogenic fermentation experiment was carried out in order to investigate the distribution of volatile acid products and gas generations with varing temperatures and pH values. The experiment was carried out using $1\%$ glucose as substrate and a pair of 3.5 liter vessle as bench scale batch reactors. The reactors were operated for 7 days at 25, 30 and $35^{\circ}C$ and at pH values of 4.0, 4.5, 5.0, 5.5 and 6.0 at each temperature conditions. Major products at all experiment pH's at $35^{\circ}C$ were acetic acids and butyric acids which together composed around $90^{\circ}F$ of total product acids. At higher pH values at $35^{\circ}C$, propionic acid reached around $10\%$. At all experiment conditions, 52 to $55\%$ of generated gases comprised of hydrogen gas and 45 to $48\%$ of carbon dioxide. With temperature increase from 25 to $35^{\circ}C$, the production rate of acetic acid increased 2.9 fold, butyric acid 22 fold, hydrogen gas 2.0 fold and carbon dioxide gas 2.3 fold. Optimum reaction conditions for highest production of acetic acid and hydrogen gas was determined to be pH 5.5 at $35^{\circ}C$.

• Journal of Environmental Science International
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• v.8 no.3
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• pp.379-386
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• 1999

The adsorption and leaching of organophosphorus pesticides (phenthoate, diazinon, methidathion) were investigated in Namwon soli(black volcanic soil), Aewol soil(very dark brown volcanic soil) and Mureung soil(dark brown nonvolcanic soil) sampled in Cheju Island. The Freundlich constant, K value, was 52.4, 31.3 and 27.7 for phenthoate, diazinon and methidathion in Namwonsoil, respectively and decreased in the order of phenthoate, diazinon and methidathion among the pesticides. The K value of phenthoate was 52.4, 15.9 and 5.9 for Namwon, Aewol and Mureung soil, respectively and was the highest for Namwon soil with very high organic matter content and cation exchange capacity(CEC). The Freundlich constant, 1/n, showed a high correlation with organic matter content, i.e., its value was less than unity for organic matter rich soil(Namwon soil) and greater than unity for organic matter poor soil(Mureung soil). Total recoveries of pesticides in soil and leachate with leaching in soil column, were in the range of about 74~86%. The leaching of pesticides was less for phenthate with high K values, and more for methidathion with low K values among the pesticides. It was slower for Namwon soil with high K values, and more for methidathion with low K values among the pesticides. It was slower for Namwon soil with high K values, and faster for Mureung soil with low K values among the soils.

• Structural Engineering and Mechanics
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• v.77 no.2
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• pp.293-304
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• 2021

Structural failure due to seismic pounding between two adjacent buildings is one of the major concerns in the context of structural damage. Pounding between adjacent structures is a commonly observed phenomenon during major earthquakes. When modelling the structural response, stiffness of impact spring elements is considered to be one of the most important parameters when the impact force during collision of adjacent buildings is calculated. Determining valid and realistic stiffness values is essential in numerical simulations of pounding forces between adjacent buildings in order to achieve reasonable results. Several impact model stiffness values have been presented by various researchers to simulate pounding forces between adjacent structures. These values were mathematically calculated or estimated. In this study, a linear spring impact element model is used to simulate the pounding forces between two adjacent structures. An experimental model reported in literature was adopted to investigate the effect of different impact element stiffness k on the force intensity and number of impacts simulated by Finite Element (FE) analysis. Several numerical analyses have been conducted using SAP2000 and the collected results were used for further mathematical evaluations. The results of this study concluded the major factors that may actualise the stiffness value for impact element models. The number of impacts and the maximum impact force were found to be the core concept for finding the optimal range of stiffness values. For the experimental model investigated, the range of optimal stiffness values has also been presented and discussed.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.23-32
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• 2007

Changes in the characteristics of dissolved organic matter was studied at selected stations in the Nakdong river basin using physical and chemical methods. Characteristics of dissolved organic matters were analysed and assessed. Production of disinfection byproducts were also investigated. Distribution of the organic compounds according to the Molecular weight(MW) indicate that MWs higher than 100K were highest with cattle excrement wastewater and MW between 100-10K were highest with waters from forest streams. Low MW compounds (Jess than 1K) were highest with the effluents from environmental facilities. Results of resin fractionation study show that acidic hydrophobic substances(AHS) were dominant in many stations. The values were higher in the samples from mainstreams and sidestreams where the influence of organic matter is higher than the water from environmental facilities. Hydrophilic neutral substances(HoN) such as hydrocarbon, pesticides and detergents were higher in the wastewater treatment facilities. HoN values of water from the forest streams were 4.7% indicating there is no synthetic pollutant.

• Journal of Environmental Science International
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• v.21 no.5
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• pp.545-553
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• 2012

Eco-efficiency considers both environmental impacts and economic values. It is a useful tool for communicating with stakeholders for business decision making. This study evaluated the eco-efficiency factor (EEF) for the energy network of a dyeing company that supplies surplus heat to a neighboring apartment during the night. This symbiosis network is one of the eco-industrial park (EIP) projects in Korea and aims to benefit local residents and the industrial complex by utilizing surplus heat. In this study, two categories were annualized. The first quantified environmental burden based on $CO_2$ emissions and quantified product value in terms of steam sales. The second used a variety of environmental factors, such as fossil fuel, water and waste, to quantify environmental burden and used steam sales to quantify value. The EEF of the symbiosis network was 1.6, using the global warming impact, and determined using the multiple variable, was 1.33. This study shows that the EEF depends on variable details of environmental burden but the values of this project were very high contrast to other business or EIP project.

• Advances in environmental research
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• v.7 no.3
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• pp.161-175
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• 2018

Krishna River is significantly affected due to Srisailam dam from past 30 years. The impact of this hydraulic structure drastically reduced the minimum flow regime on the downstream, which made the river nearing to decaying stage. In the present paper, Environmental Flow called minimum flow values released for the dam are estimated with the help of three hydrological methods viz., Range of variability Approach (RVA), Desktop Reserve Model (DRM), and Global Environmental Flow Calculator (GEFC). DRM method suggested considering the intermediate values obtained from among the three methods to preserve the ecosystem on the downstream of the river, which amounts to an average annual allocation of 9378 Million Cubic Meter (MCM) which is equal to 23.11% of mean annual flow (MAF). In this regard GEFC and RVA methods accounted for 22% and 31.04% of MAF respectively. The results indicate that current reservoir operation policy is causing a severe hydrological alteration in the high flow season especially in the month of July. The study concluded that in the case of non-availability of environmental information, hydrological indicators can be used to provide the basic assessment of environmental flow requirements. It is inferred from the results obtained from the study, that the new reservoir operations can fulfil human water needs without disturbing Environmental Flow Requirements.

• Journal of Environmental Science International
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• v.33 no.6
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• pp.345-353
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• 2024

As biodiversity loss has been highlighted as a global risk, biodiversity activities are gaining attention as a part of companies' Environmental, Social, and Governance (ESG) related management. This study evaluates various biodiversity activities of corporations based on domestic and international indicators. We present the role of corporations expressly in afforestation activities and suggest additional information that should be disclosed for the accurate verification of environmental values by third parties. KT&G was selected as the subject of the evaluation. The 4th National Biodiversity Strategy was used as a domestic indicator, and GRI Standard 304 as an international indicator. Companies can play a leading role in planning, implementing, and monitoring afforestation activities and should further disclose the species composition of the forests created and the age of the seedlings to enhance the credibility of the environmental values stated in their sustainability reports.

• Hwankyungkyoyuk
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• v.14 no.2
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• pp.76-94
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• 2001

Promoting positive values, attitudes, participation and personal actions on the basis of the acquisition of one's knowledge and skills is emphasized on teaching environmental education. To complete this purpose of environmental education, it is necessary not only to use various and practical educational resources, but also to develop information system, with multimedia and internet, which are effective for learning. This research attempts to assess the consistency of planning, organization and operation of integrated program for social environmental education which was developed for the necessities mentioned above. We surveyed about the accuracy of contents, usefulness, convenience and easiness of Integrated program for social environmental education. Also, we used a questionnaire to clarify the values and attitudes of respondents after they took environmental education. Then, technically, descriptive statistical method has been used to analyze the results of these surveys. Finally, we conduct an examination of the distribution of chi-square to verify the relationship between the learner's experience of using computer and one's concern about environmental issues. The results of this program, developed by research team, can be assessed by following five basic elements: usefulness, practicality, appropriation, efficiency and effectiveness. More than 90% of respondents said that this program is convenient and easy to loam. Also, more than 85% of whole respondents identified that after teaming this program they recognized more clearly what the main contents of environmental education are. In addition, we got positive response from 93% of respondents that they could understand environmental problems. On the other hand, values and attitudes of respondents have not improved a lot after the environmental education compared with the remarkable change in their recognition and understanding of environmental issues; only 34% of respondents responded that they changed their life style for making better environment after teaming this program. But it is clear that they understand much better about the environmental policy after they are educated. Developed by using information system, this integrated program for social environmental education may get different results according to a respondent's experience of using computer. Therefore, the more a respondent got a chance to use computer for a long period of time, the more he/she gave positive evaluation on the convenience and easiness of this program. However, there was no certain relationship between the frequence of using computer and one's understanding of environmental issues. Futhermore, a person who has constant concerns about environmental problems showed more positive attitudes against the understanding of environmental education. This integrated program for social environmental education, characterized by integrated, specialized and efficient educational system, can also be used as a curriculum or teaching materials for environmental education for adults; especially, it would be appropriate for teaching learners at all levels, who have different personal characteristics, to let them acquire virtual education by using information system.

• Atmosphere
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• v.26 no.4
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• pp.697-709
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• 2016

This study estimates and evaluates the extreme value of 30 m-resolution daily maximum and minimum temperatures over South Korea, using inverse distance weighting (IDW), parameter-elevation regression on independent slopes model (PRISM) and generalized extreme value (GEV) method. The three experiments are designed and performed to find the optimal estimation strategy to obtain extreme value. First experiment (EXP1) applies GEV firstly to automated surface observing system (ASOS) to estimate extreme value and then applies IDW to produce high-resolution extreme values. Second experiment (EXP2) is same as EXP1, but using PRISM to make the high-resolution extreme value instead of IDW. Third experiment (EXP3) firstly applies PRISM to ASOS to produce the high-resolution temperature field, and then applies GEV method to make high resolution extreme value data. By comparing these 3 experiments with extreme values obtained from observation data, we find that EXP3 shows the best performance to estimate extreme values of maximum and minimum temperatures, followed by EXP1 and EXP2. It is revealed that EXP1 and EXP2 have a limitation to estimate the extreme value at each grid point correctly because the extreme values of these experiments with 30 m-resolution are calculated from only 60 extreme values obtained from ASOS. On the other hand, the extreme value of EXP3 is similar to observation compared to others, since EXP3 produces 30m-resolution daily temperature through PRISM, and then applies GEV to that result at each grid point. This result indicates that the quality of statistically produced high-resolution extreme values which are estimated from observation data is different depending on the combination and procedure order of statistical methods.