• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.192-199
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• 2010

This research produced internal model tester ($2.0m{\times}2.0m{\times}1.0m$) to evaluate the field application of Paju Unjeong District water recycling system for small streams eco-friendly river bed disparity method for the first time in Korea and conducted comparative analysis of the Paju Unjeong District water recycling system field test results and infiltration rate result of internal tests by each rainfall intensity following surface material. Infiltration rate result of internal tests concrete pavement by rainfall intensity following surface material, asphalt pavement, bentonite mate, stabilized soil construction and mixed soil construction manifested low infiltration rate. On the contrary, compaction soil, grassland and water permeable packaging materials resulted in significant amount of infiltration rate. As for the field permeability test results, they were manifested similar tendency as indoor permeability test results and they satisfied the standard for standard of water permeability of domestic disparity facility (less than $1.0{\times}10-7cm$/sec). As compaction rate increased, unconfined compression strength increased as well while coefficient of water permeability decreased.

• Resources Recycling
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• v.13 no.5
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• pp.51-56
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• 2004

Economic benefits of the dry bottom ash handling system over the wet bottom ash handling system in a new 500MW${\times}$2units pulverized coal thermal power plant in Korea were evaluated. The higher initial capital cost in the dry bottom ash handling system was estimated. However, this higher initial capital costs would be compensated with reductions of the operating cost mainly due to the recycling of bottom ash. Economic analysis showed that the payback period of 4.9 years and the internal rate of return at 21.1% were expected for the additional initial capital cost of the dry bottom ash handling system.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.2
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• pp.73-78
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• 2023

The cosmetics industry faces a significant challenge in addressing the decreased recycling rate of cosmetic containers due to the composite materials used to meet consumers' aesthetic satisfaction. To address thees issues, eco-friendly packaging solutions such as refill packaging and single-material use have been developed. However, the market for eco-friendly cosmetics packaging requires a product that meets consumers' demands for aesthetics, sensitivity, and eco-friendliness while also performing as well as existing products. This study presents a solution to the challenge of the decreased recycling rate of cosmetic containers by developing a new cosmetic packaging product for cream formulations. The product features an easily separable and dischargeable internal refill container, while maintaining the design aesthetics of the external container. Through various tests, the product was shown to be of equivalent quality and performance to existing cream cosmetic packaging, with no leakage or defects observed. Furthermore, the use of a single-material polypropylene refill container is expected to contribute to the improvement of the plastic recycling rate.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.30-36
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• 2006

This study was carried out to evaluate the performance of Modified Ludzsck Etinger (MLE) process with waste oyster shell media in aerobic tank. Influent flow was 36 L/d and the order of reactor was anoxic, aerobic and sedimentation tank and unit hydraulic retention time was 2 hr, 6 hr and 4 hr, respectively. Sludge recycling rate in sedimentation tank and internal recycling rate were 100%. Media fill rate in aerobic tank was 5%, 10% and 17% and fluid MLSS concentration in aerobic tank was 3000~4000 mg/L. Average TCOD removal rate was 91~93%, TBOD 92~96%, SS 95~96% and when media fill rate was 10% or more, in organic compound removal it could satisfy with wastewater discharge standard. Average total nitrogen removal rate was 70~76% and average total phosphorous removal rate was 58~65%. With media fill rate increasing, total phosphorous average removal rate also increased. For it was that released calcium ion from waste oyster shell reacted with soluble phosphorous. From these experiment results, the MLE process using waste oyster shell as media is a practical method for advanced sewage treatment in rural area.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.362-373
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• 2012

The ship recycling industry is growing rapidly. It is estimated that the International Maritime Organization's (IMO) decision to phase-out single hull tankers by 2015 will result in hundreds of ships requiring disposal. At present, the ship recycling industry is predominantly based in South Asia. Due to the bad practice of current scrapping procedure, the paper will highlight the harm occurring to health, safety and environment. The efforts of the Marine Environment Protection Committee (MEPC) which led to the signing of the Hong Kong International Convention are also reviewed. The criteria and standards required to reduce the risk and damage to the environment are discussed and a proposed plan for the safe scrapping of ships is then presented. A technological and economic study for the ship recycling in Egypt is carried out as a case study. This includes the ship recycling facility size and layout. The equipment and staff required to operate the facility are also evaluated. A cost analysis is then carried out. This includes site development, human resources, machineries and equipment. A fuzzy logic approach is used to assess the benefits of the ship breaking yard. The use of the fuzzy logic approach is found suitable to make decisions for the ship breaking industry. Based on given constraints, the proposed model has proved capable of assessing the profit and the internal rate of return.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.5
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• pp.591-595
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• 1997

An ex vivo assay determining the flavin-containing monooxygenase (FMO) activity in perfused rat liver has been developed by assessing the rate of thiobenzamide S-oxide (TBSO) formation from the infused thiobenzamide (TB). The hepatotoxicity by TB or TBSO was not a critical factor for maintaining the FMO activity for up to 50 min. The FMO activity expressed in nmoles TBSO produced/g liver/min was the same for the recycling and non-recycling perfusion. This implies that reduction of the oxidized TBSO back to the parent compound (TB) is negligible. Hydrolysis of the collected perfusates with either ${\beta}-glucuronidase$ or arylsulfatase did not increase the TBSO level and thus, TBSO does not appear to undergo conjugation either to glucuronide or sulfate esters. Thus, measuring the rate of TB S-oxidation in the isolated perfused liver with 1 mM TB for 50 min provides a useful tool for evaluation of the hepatic FMO activity in the absence of hepatic necrosis and without the interferences caused by further conjugation or back reduction of the TBSO to the parent TB.

• Korean Journal of Materials Research
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• v.12 no.10
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• pp.796-802
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• 2002

Effect of nine different cations to the formation of iron oxyhydroxide was studied using Mossbauer spectroscopy, XRD and BET. The Redox Potential and pH were measured for the determination of the internal reaction rate, as well. The phases of iron oxyhydroxide could not be the same with each other, due to the present of different cations in solution. Although the oxyhydroxide compound were composed of the same phases, the fraction of each phase was different from each other. The internal reaction rate was varied by the substitution of cation. It could be a cause of the different phase and particle size of oxyhydroxide compound.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.89-97
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• 2010

In this study, to investigate the effect of chemical pretreatment for livestock wastewater, laboratory scale test for ozonation and linked treatment of sewage were conducted. and the results were obtained as follows. The ozonation of livestock wastewater showed the COD removal rate per hour to be 17%, 78% and 62% at each pH 4, 7 and 10, respectively. With transformation of NBDCOD to biodegradable BDCOD by ozonation, the ratio of SCODcr/TCODcr was increased from 26% to 38%. Accordingly, pretreatment of livestock wastewater affected to the biological post treatment process to elevate removal efficiency by transformation of nonbiodegradable mass to biodegradable mass. As the results of linked treatment of pre-ozonated livestock wastewater and sewage in the MLE process, the treatment efficiencies of TCODcr 93.8%, T-N 74.3%, T-P 89.7%, SS 97.5% were earned at 100% of internal recycle rate. When the internal recycle rate was increased to 150%, the treatment efficiencies of TCODcr 94.5%, T-N 54.5%, T-P 70.8%, SS 98.5% were earned. Also the removal efficiencies of TCODcr 92.6%, T-N 83.1%, T-P 81.9%, SS 98.5% were earned as the internal recycle rate was increased to 200%. Especially, nitrogen removal efficiency in the linked treatment showed 74.3%, 54.5%, 83.1% at 100%, 150% and 200% of internal recycle ratio, respectively, which revealed the tendency of higher removal efficiency than that of sewage treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.1
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• pp.45-51
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• 2015

In this study, continuous microbial fuel cells (MFCs) were operated using non-precious metal catalysts such as iron(II) phthalocyanine (FePc) and cobalt tetramethoxyphenylporphyrin (CoTMPP)) as alternative cathode catalysts for platinum. To evaluate MFCs performance, operational conditions of organic loading rate (OLR) (0.5~3 g COD/L/d) and hydraulic retention rate (HRT) (0.25~1 day) were changed. Power density of MFCs were determined by cathode electrode performance. The maximum power density was $3.3W/m^3$ with platinum at OLR 3 g COD/L/d. Given each HRTs at 1 g COD/L/d, FePc showed to be a better alternative for platinum than CoTMPP because the power density of MFC with FePc was similar to that of MFC with platinum. CoTMPP catalyst, however, showed the lowest power density due to increase of internal resistance during continuous operation.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.251-263
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• 2013

The internal reflux effect on dialysis through the retentate phase of a countercurrently cross-flow rectangular module is investigated. Theoretical analysis of mass transfer in cross-flow devices with or without recycling is analogous to heat transfer in cross-flow heat exchangers. In contrast to a device without reflux, considerable mass transfer is achievable if cross-flow dialyzers are operated with reflux, which provides an increase in fluid velocity, resulting in a reduction in mass-transfer resistance. It is concluded that reflux can enhance mass transfer, especially for large flow rate and feed-concentration operated under high reflux ratio.