• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.190-196
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• 2007

As the number of aged-housing has been rapidly increased, many kinds of defects and problems such as degeneration of housing environment, structural performance, and equipment performance have been appeared. The reconstruction as the way to improve the aged-housing has been used mostly because the legal process of the reconstruction is relatively easy. On the other hand, it has caused problems such as the lack of natural aggregates, the environmental damages owing to construction wastes, the loss of national resources, and the lack of the housing for rent nearby the reconstruction area. This problems limit active tying into the reconstruction business at present in the industrial and political perspective. In this context, it is necessary to revitalize the remodeling rather than the reconstruction. In order to reach this objective, this research aims at identifying the user-oriented performance for the housing and deducing the core technology. It is expected that the result of this research can contribute to more revitalize the remodeling as tying researches in terms of design, structure, equipment, and construction.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.183-189
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• 1999

A study on the destruction of organic cation and anion exchange resins by electro-generated Ag(II) as a mediator was carried out to develop the ambient-temperature aqueous process, known as Ag(II)-mediated electro-chemical oxidation (MEO) process, for the treatment of a large quantity of spent organic ion exchange resins as the low and Intermediated-level radioactive wastes arising from the operation, maintenance and repairs of nuclear facilities. The effects of controllable process parameters such as applied current density, temperature, and nitric acid concentration on the MEO of organic ion exchange resins were investigated. The cation exchange resin was completely decomposed to $CO_2$. The current efficiency increased with a decrease in applied current density while nitric acid concentration and temperature on the MEO of cation exchange resin did not affect the MEO. On the other hand, anion exchange resins were decomposed to CO and $CO_2$. The ultimate conversion to CO was about $10\%$ regardless of temperature. The destruction efficiencies to $CO_2$ were dependent upon temperature and the effective destruction of anion exchange resin could be obtained above $60^{\circ}C$.

• Journal of Environmental Policy
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• v.9 no.3
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• pp.69-114
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• 2010

This study investigates the voluntary corporate disclosure of environmental information via stand-alone environmental reports or company web-sites. Quality of disclosure was assessed using the content analysis index proposed by Clarkson et al. (2008) based on GRI guidelines. Descriptive statistics on disclosure scores by category suggest that the level of disclosure is low relative to the expectation implied by the GRI reporting guidelines, and points to the need for improvement in the future. Specific areas where improvement is required include the disclosure of environmental performance indicators. Corporate environmental performance was measured in terms of the percentage of toxic wastes that was treated or processed by each firm and economic performance, by industry-adjusted annual return, which was subject to a series of association tests designed to explore the interrelations among environmental disclosure, environmental performance, and economic performance. The individual equation approach based on OLS procedures suggests a positive association between environmental performance and the level of discretionary environmental disclosures, which is not the case between environmental and economic performance. An integrated analysis using simultaneous equations approach does not indicate any significant relationships among three constructs, suggesting the lack of endogeneity, inconsistent with Al-Tuwaijri et al. (2004). Additional analysis assesses the level of environmental disclosure made in footnotes to the audited annual reports, which suggests that the quality of disclosure is very low and that footnote disclosure does not serve as a meaningful channel for the provision of corporate environmental information.

• The Korean Journal of Emergency Medical Services
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• v.12 no.3
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• pp.99-113
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• 2008

In order to protect Rescue 119 workers exposed on the spot from potential infection, this study identified their awareness and practices of infection control so that it could help preventing them from infection and also provide basic materials necessary for pre-hospital infection control. This study applied questionnaire survey to total 215 Rescue 119 workers at fire stations in Jeonbuk province, Jeonnam province and Gwangju city from July 14 to Sept. 14, 2006 for the benefit of data collection. The questionnaire about possible associations between awareness and practices of infection control consisted of total 46 times across 6 categories such as washing hands during emergency activities ; fluid therapy and injection ; respirator maintenance; individual hygienics ; disinfectant supplies and equipments maintenance ; and control of infectious wastes. And collected data were processed using SPSS statistic program to analyze frequency and percentage, mean and standard deviation, Pearson's correlation coefficient, t-test and one-way ANOVA. As a result, this study came to the following conclusions : In terms of awareness about infection control, our respondents showed highest awareness about infectious waste control, and also showed highest level of practices in washing hands during emergency activities. Throughout all domains, awareness means were higher than practice means. In particular, infectious waste control was the domain of significant differences between awareness and practices. In terms of associations between awareness and individual characteristics, it was found that female rescue worker group and hospital/general hospital career group (before joining the Rescue 119) showed significantly higher awareness on statistic level. In regard to associations between individual characteristics and practices, it was found that female rescue worker group showed higher level of practices than male group on statistic level. This study also analyzed correlations between rescue workers' awareness and practice of infection control. As a result, it was found that the higher awareness was in correlations with the higher practices across all 6 domains including washing hands. In addition, the higher awareness of a questionnaire item was in significantly positive correlations with the higher practice of other items. However, our respondents showed high awareness about anti-infection, but low practices in reality. This indicates necessity of devising possible solutions to improve the practices as much as awareness. Especially, it was noted that major reasons for insufficient practices of infection control guideline come from unhabituated practices and lack of supports for infection-preventing supplies and protective device (mask, etc). Hence, it is necessary to provide more infection-preventing supplies for local rescue workers sufficiently, in parallel with steady habituation of infection control. Furthermore, it is required to manage and study infection control policies even at pre-hospital step in efforts for effective infection control, education and activities.

• Resources Recycling
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• v.26 no.2
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• pp.11-17
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• 2017

Many problems are occurred by using industrial by-product and municipal solid waste in the cement manufacturing process. The main components of chlorine by-pass dust generated by the use of the wastes are $K^+$, $Cl^-$, and a slight amount of heavy metals is also contained. In terms of waste recycling, it is necessary to eliminate the heavy metals. Therefore, in this study, the experiments for the removal of heavy metals from KCl which was produced by chlorine by-pass dust were conducted. In order to find optimum conditions for the removal of heavy metals, we have controlled the amount of water and precipitator. The type and concentration of heavy metals in KCl were analyzed. The concentration of heavy metals decreased as amount of precipitator increased. The heavy metals such as Pb, Cd, and As were not detected in dust A and B, when the mixing ratios between dust A(B) and water were controlled to be 1:2 (1:2, 1:3.5) with the addition of 3% precipitator (NaOCl).

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.219-226
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• 2020

Over the last decades, great efforts have been devoted to reuse industrial wastes and by-products from various industries as supplementary cementitious materials in order to reduce carbon dioxide(CO₂) emission by reducing the use of Portland cement in construction. Oyster shell waste, originating from the fishery industry, is available in huge quantities in certain areas, and is generally discarded or landfilled. In this study, we aimed to reuse oyster shell as an alternative to limestone in limestone calcined clay cement(LC³). The oyster shell calcined clay cement(OC³) paste were produced and were characterized via X-ray diffraction, isothermal calorimetry, compressive strength tests, and thermogravimetry. The results revealed that OC³ pastes exhibited similar strength development and reactivities by pozzolanic reaction with LC³, which implies that oyster shell could be used as a substitute for limestone in LC³.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.2
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• pp.227-234
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• 2020

Under consideration of construction waste recycling, candidate secondary products applicable for the civil and construction areas can be reliably employed based on the recycling cost analysis. For the validation purpose, probability-based cost analyses were performed to estimate recycling cost profit considering uncertainties. When recycling construction wastes, the costs at each stage are fully dependent on target products to be adopted. To achieve commercialization of each product, its quality has to be improved with economic efficiency through accurate evaluation of input costs. Based on the probabilistic recycling cost analysis, the cost benefit for target products was estimated with waste classification cost, transportation cost to recycling treatment facilities and production cost. All necessary information on the cost analysis were collected from literature, disclosure, and existing recycling companies. In addition, a cost difference between recycled and non-recycled events was made. As a result, a probability-based recycling cost estimate for candidate secondary products was herein presented.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.4
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• pp.203-212
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• 2005

Anthropogenic emissions of greenhouse gases, particularly carbon dioxide($CO_2$) which arises mainly as wastes from the fossil fuel burning processes, are causing global warming. The effects of global warming become increasingly felt all over the world including sea level rise and extreme weather. The more direct consequences of the elevated atmospheric $CO_2$ on the ocean is the acidification of the surface ocean which brings a far reaching adverse impact on the life at sea and probably on the whole ecosystem of the planet. Improvement in energy efficiency and use of alternative energy sources are being made to reduce $CO_2$ emissions. However, a rapid transition to alternatives seems unachievable within a few decades due to the constraints on the associated technology and socio-economic factors in the world, since fossil fuels make up approximately 85% of the world's commercial energy demands. It has now been recognized that capture and geological sequestration of $CO_2$ could significantly reduce its emissions from fossil fuel utilization and therefore provides the means to rapidly achieve large reductions in $CO_2$ emissions(excerpts from London Convention, LC/SG 28, 2005). In Korea, well-developed sedimentary basins are spread over the vast continental shelf and slope regions, whereas, the land is densely populated and limited in area. Consequently, the offshore area is preferred to the land for the sites for geological sequestration. The utilization of the offshore area, however, may be subject to international agreements including London Convention. In this paper, the recent trends in technologies and regulations for $CO_2$ capture and geological sequestration are described to encourage its applications in Korea.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.258-263
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• 2004

Bioassay was employed to assess toxicity of soil which had been treated with sewage sludges for seven years. The $Microtox^{(R)}$ and root elongation test of lettuce (Lactuca Sativa.) elucidated that the intensity of soil toxicity was closely related with the types and amount of sewage sludges applied. Both bioassay methods proved to be useful in an assessment of soil toxicity and were consistent to some extent with the conventional chemical analysis methods. $EC_{50}$ values resulted from $Microtox^{(R)}$ were highly correlated with concentration of heavy metals in soils amended with sewage sludges : Cu ($r^2=\;0.86^{**}$), Cr ($r^2\;=\;0.84^{**}$), Ni ($r^2\;=\;0.83^{**}$), and Zn ($r^2\;=\;0.69^{**}$). This demonstrated that both bioassay techniques could be employed as tools for soil toxicity assessment when the soil was exposed to solid wastes such as sewage sludge.

• Resources Recycling
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• v.25 no.3
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• pp.29-36
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• 2016

The characteristics analysis and pH neutralization test were carried out to use of slurry generated from recycling processes of construction wastes. D (5.0) of raw sludge was $42.4{\mu}m$ and over 60 % of sludge distribute under 45 um (-325 mesh). Muscovite and carbonate minerals were main minerals of fine particles, and the portion of carbonate minerals increased as particle size decreased. Although the more heavy metals were observed in the finer particle size, the contents was found to be less than Korean contaminated soil regulation (area 2). The effects of flocculants addition for accelerating solid-liquid separation were negligible because the slurry already contains excess of coagulant added in the waste concrete recycling process. It was difficult to neutralize the sludge supernatant due to high pH (about 12) by adding acids, but the introduction of $CO_2$ decreased the pH to 8.5, The precipitate recovered during $CO_2$ introduction was determined to be $CaCO_3$ with XRD, and it indicates that high pure $CaCO_3$ could be obtained during the process.