• Communications for Statistical Applications and Methods
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• v.20 no.2
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• pp.115-127
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• 2013

This paper provides an effective stock portfolio screening tool for socially responsible investment (SRI) based upon corporate social responsibility (CSR) and financial performance. The proposed approach utilizes nonparametric frontier models. Data envelopment analysis (DEA) has been used to build SRI portfolios in a few previous works; however, we show that free disposal hull (FDH), a similar model that does not assume the convexity of the technology, yields superior results when applied to a stock universe of 253 Korean companies. Over a four-year time span (from 2006 to 2009) the portfolios selected by the proposed method consistently outperform those selected by DEA as well as the benchmark.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.167-168
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• 2022

Recently, starting with the permanent suspension of Gori 1 in Korea, the importance of the disposal of concrete structures in nuclear power plants has emerged, and environmental and safety are required to be proved accordingly. Safe radioactive waste disposal technology that immobilizes harmful radioactive elements, which are by-products of nuclear power, inside a solid matrix and recycling measures are needed to secure an efficient waste disposal space. This study was conducted to confirm whether recycled cement generated in the process of radioactive concrete treatment can be used as a solidifying material for radioactive waste treatment. In order to simulate the concrete exposed to radiation, aqueous solutions of Di-water, CsCl 1M, and CoCl₂ 1M were used as blending water at W/B 0.5. Tricalcium phosphate and Prussian blue were substituted with 5 wt.% based on the weight of recycled cement as a binder to improve solidification performance, and their hydration characteristic was analyzed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.2 s.25
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• pp.157-163
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• 2006

The scenario of $CO_2$ disposal in the deep-sea are thought to be possible method to reduce atmospheric $CO_2$ concentrations. However, it is necessary to clarify the effects of elevated $CO_2$ concentrations on both marine organisms and marine ecosystems. In this paper the literatures on the biological impact of elevated $CO_2$ concentrations in seawater and recent studies on the effects of elevated $CO_2$ concentrations on marine animals are reviewed. Elevated $CO_2$ concentrations may affect the physiological functions of marine animals such as acid-base regulation, blood oxygen transport and respiratory system, and ultimately lead to the death of marine animals. Although the fish used in the early studies on $CO_2$ effects are temperate, shallow-water species, deep-sea species should be experimented for the future study on $CO_2$ sequestration in the deep ocean.

• Membrane Journal
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• v.20 no.2
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• pp.127-134
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• 2010

This study is conducted about the system that reduces organism after fermenting food waste from a food waste disposal equipment, divides gas made when food waste is fermented into gas and water, and then sends gas to a reactor again, condenses water, and apply it to the MBR system with submerged MF hollow fiber membranes. A submerged MF hollow fiber membrane module was installed to a food waste disposal equipment and a water treatment system made by Bio Hitech Co,. Ltd. to process food waste generated from a staff cafeteria in a H institute for 90 days. For initial seeding of a food waste disposal equipment, 305 kg of rice bran, chaff, and sawdust as well as 1,648 kg of food were input during the operation, and 1,600 L of condensed wastewater occurred. Fermented by-product after finishing running a food waste disposal equipment was 386 kg and its reduction was shown to be 80%. The organism was processed by applying submerged MF hollow fiber membrane module to the MBR system of condensed wastewater, and the result shows reduction rates were BOD 99.9%, COD 97.5%, SS 98.6%, T-N 54.6% and T-P 34.7% and the total colon bacillus was perfectly eliminated.

• Journal of Radiation Protection and Research
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• v.45 no.4
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• pp.178-186
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• 2020

Background: Reactor pressure vessel (RV) with internals (RVI) are activated structures by neutron irradiation and volume contaminated wastes. Thus, to develop safe and optimized disposal plan for them at a disposal site, it is important to perform exact activation calculation and evaluate the dose rate on the surface of casks which contain cut-off pieces. Materials and Methods: RV and RVI are subjected to neutron activation calculation via Monte Carlo methodology with MCNP6 and ORIGEN-S program-neutron flux, isotopic specific activity, and gamma spectrum calculation on each component of RV and RVI, and dose rate evaluation with MCNP6. Results and Discussion: Through neutron activation analysis, dose rate is evaluated for the casks containing cut-off pieces produced from decommissioned RV and RVI. For RV cut-off ones, the highest value of dose rate on the surface of cask is 6.97 × 10-1 mSv/hr and 2 m from it is 3.03 × 10-2 mSv/hr. For RVI cut-off ones, on the surface of it is 0.166 × 10-1 mSv/hr and 2 m from it is 1.04 × 10-1 mSv/hr. Dose rates for various RV and RVI cut-off pieces distributed lower than the limit except the one of 2 m from the cask surface of RVI. It needs to adjust contents in cask which carries highly radioactive components in order to decrease thickness of cask. Conclusion: Two types of casks are considered in this paper: box type for very-low-level waste (VLLW) as well as low-level waste (LLW) and cylinder type for intermediate-level waste (ILW). The results will contribute to the development of optimal loading plans for RV and RVI cut-off pieces during the decommissioning of nuclear power plant that can be used to prepare radioactive waste disposal plans for the different types of wastes-ILW, LLW, and VLLW.

• Advances in environmental research
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• v.9 no.3
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• pp.175-189
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• 2020

Municipal solid waste disposal is considered as one of the most important risks for environmental contamination which necessitates the development of strategies to reduce destructive consequences on the ecosystem as related especially to heavy metal accumulation. This study investigates heavy metal (i.e., As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) accumulation in the Tonekabon region, NW of Iran that is related to city waste disposal and evaluates the environmental impact in the Caspian Sea coastal region. For this purpose, after performing field studies and collecting 50 soil specimens from 5 sites of the study area, geochemical tests (i.e., inductively coupled plasma mass spectrometry, atomic absorption spectroscopy and x-ray fluorescence) were conducted on the soil specimens collected from the 5 sites (named as Sites A1, A2, A3, A4 and A5) and the results were used to estimate the pollution indices (i.e., geo-accumulation index, normalized enrichment factor, contamination factor, and pollution load index). The obtained indices were utilized to assess the eco-toxicological risk level in the landfill site which indicated that the city has been severely contaminated by Cu, Mn, Ni, Pb and Zn. These levels have been developed along the stream towards the nearshore areas indicating uptake of soil degradation. The heavy metal contamination was classified to range from unpolluted to highly polluted, which indicated serious heavy metal pollution in the study area as related to municipal solid waste disposal in Tonekabon.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.511-517
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• 1992

Ethanol was utilized by mixed rumen microbes, but addition of pentachlorophenol (25 mg/l), a methanogen inhibitor, suppressed the utilization of ethanol. Carbon monoxide (50% of the gas phase), a hydrogenase inhibitor, more strongly suppressed the utilization of ethanol, propanol, and butanol. These results suggest that the major ethanol utilizers are $H_2$ producers. Ethanol utilization was depressed at low pH (below 6.0). Since methanogens were shown to be relatively resistant to low pH, it appears that ethanol utilizers are particularly sensitive to low pH. Ruminococcus albus and R. flavefaciens in mono-culture produced ethanol from carbohydrate (glucose and cellobiose), even when a high level (170 mM) of ethanol was present. Ethanol was not utilized even in the absence of carbohydrate, but the co-culture of these bacteria with methanogens resulted in the utilization of ethanol, i.e., when $H_2$ was rapidly converted to $CH_4$, R. albus and R. flavefaciens utilized ethanol. These results suggest that ethanol is utilized when the electrons liberated by the oxidation of ethanol are rapidly removed, and ready electron disposal in ethanol-utilizing, $H_2$-producing bacteria is accomplished by the interspecies transfer of $H_2$.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.153-153
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• 2010

The world is moving towards a post-carbon society and needs clean and renewable energy for sustainable development. There are many methodological approaches which are helping this shift based on analyzed data about energy resources and which focus on limited types of energy including liquid fossil, solid fossil, gaseous fossil, and biomass (e.g. IPCC Guidelines, ISO 14064-1, WRI Protocol, etc.). We should also consider environmental impact (e.g. greenhouse gas emissions, water use, etc.) and the economic cost of the renewable energy to make a better decision. Recently, researchers have addressed the environmental impact of new technologies which include photovoltaics, wind turbines, hydroelectric power, and biofuel. In this work, we analyze the environmental impact with a carbon emission factor to present a correlation between $CO_2$ emission and the cost of energy resources standardized by the energy output. In addition, we reviewed Life Cycle Assessment (LCA) as another methodology. Researchers who are studying energy systems have ignored the impacts of entire energy systems, e.g. the extraction and processing of fossil fuels. In power sector, the assessment should include extraction, processing, and transportation of fuels, building of power plants, production of electricity, and waste disposal. Therefore LCA could be more suitable tool for energy cost and environmental impact estimation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.270-278
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• 2006

The idea of carbon dioxide sequestration in the ocean is proposed to be an effective mitigation strategy to counteract potential global warming due to the greenhouse effect. Therefore, in the present study, calculations of the dissolution behavior of carbon dioxide when liquid carbon dioxide is released at 1,000m and 1,500 m in depth. by fixed pipeline are peformed. The results show the liquid $CO_2$ injected in the ocean becomes $CO_2$ bubble at between 350m and 500m in depth, and the injection from a moving ship is a more effective method of dissolution than through a fixed pipeline. It so also noted that the ultimate plume generated from $CO_2$ bubbles repeats expansion and shrinking due to the peeling from a fixed pipeline.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.643-650
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• 2003

We analyzed the amount of environmental loads, and the amount of energy consumption through life cycle assessment from a discharge stage to the ultimate disposal to municipal solid waste in Seoul. We carried out inventory analysis of the amount of environmental loads that made the object range collection, intermediate treatment, and the final treatment, and took into consideration each stage exceptions CO$_2$ and NOx , the amount of SOx discharge, and energy consumption. We applied the data of an object model, and acquisition processed the scale of an object model suitably and applied to it to difficult data using the data of the Yokohama City incineration plant in Japan. The amount of environmental loads per Iton of municipal waste were analyzed CO$_2$ 0.4C-ton, SOx 0.4kg and NOx 0.8kg. Moreover, the amount of energy consumption which is 2.4Gcal was computed.