• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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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.

• 자원리싸이클링
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• 제13권5호
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• pp.51-56
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• 2004

국내 석탄화력발전에서 발생되는 바닥재 재활용의 경제성을 평가하고자 신설 500 MW${\times}$2기 유연탄 화력발전설비를 대상으로 바닥재 재활용이 가능한 건식처리시스템 도입의 경제성을 충수중력식 습식처리시스템과 비교하여 검토하였다. 신규발전설비에 건식처리시스템 도입 시 시설투자비는 습식처리시스템의 약 150% 수준으로 초기투자비는 더 소요되나, 바닥재 재활용을 통한 판매이익을 고려한 연간시설운영비는 습식처리시스템의 약 17%까지 절감되는 것으로 예측하였다. 이를 기초로 경제성 분석을 수행한 결과 건식처리시스템 도입 시 추가로 소요되는 초기투자비는 4.8년에 회수가 가능하며 투자이익률은 21.1%로 평가되었다.

• 한국포장학회지
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• 제29권2호
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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.

• 한국물환경학회지
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• 제22권1호
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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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• 제4권4호
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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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• 제1권5호
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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.

• 한국재료학회지
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• 제12권10호
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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.

• 유기물자원화
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• 제18권1호
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• pp.89-97
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• 2010

본 연구에서는 오존을 이용하여 축산폐수를 전처리하고 일반하수와 연계하여 처리하였을 때 처리효율을 실험실 규모의 장치를 이용하여 비교 분석하였으며 결과는 다음과 같다. 축산폐수의 오존산화 결과 대상폐수의 pH를 산성(pH4), 중성(pH7), 알칼리성(pH10)으로 변화시켰을 때 각각 COD제거율은 시간당 17%, 78%, 62% 로 분석되었다. 오존산화에 의해 NBDCOD 중 일부가 미생물이 분해가능한 BDCOD 로 전환되어 SCODcr/TCODcr 비는 26%에서 약 38%로 증가하였다. 따라서, 오존산화에 의한 축산폐수의 전처리는 난분해성 물질을 생물학적 분해 가능한 물질로 일부 전환시키며 후단 생물학적 처리 단계에서의 제거효율을 높일 수 있는 영향을 미치는 것으로 분석되었다. 오존산화처리된 축산폐수와 하수와의 연계유입수를 MLE(Modified Ludzack-Ettinger) 공정으로 처리한 결과, 내부반송 100%일 때 TCODcr 93.8%, T-N 74.3%, T-P 89.7%, SS 97.5%의 처리효율을 나타냈다. 또한 내부반송율을 150%로 증가시켰을 때 처리효율은 각각 94.5%, 54.5%, 70.8%, 98.5% 로 나타났고, 200%로 증가시켰을 때 처리효율은 각각 92.6%, 83.1%, 81.9%, 98.5% 로 나타났다. 연계유입수를 원수로 사용한 경우 특히 질소제거율은 내부반송율 100%, 150%, 200%에서 각각 74.3%, 54.5%, 83.1%로 나타났으며, 모든 경우에 있어 일반하수를 원수로 사용한 경우보다 질소제거율이 우수한 것으로 분석되었다.

• 유기물자원화
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• 제23권1호
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• pp.45-51
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• 2015

본 연구에서는 비귀금속 촉매인 iron(II) phthalocyanine (FePc)와 cobalt tetramethoxyphenylporphyrin(CoTMPP)를 환원전극촉매로 이용하여 미생물연료전지의 연속운전을 진행하였다. 연속운전은 유기물 부하 (0.5~3 g COD/L/d)와 HRT (0.25~1 day)의 조건을 달리 운전하여 미생물연료전지의 성능을 평가하였다. 미생물연료전지의 전력밀도는 환원전극의 성능에 크게 영향을 받았으며, 최대전력밀도는 $3.3W/m^3$로 백금을 사용한 미생물연료전지에서 나타났다. 하지만, HRT의 조건을 달리 한 실험에서 FePc를 사용한 미생물연료전지가 백금을 사용한 미생물연료전지와 유사한 성능을 나타냈으며, 연속운전에서 백금 촉매를 대체할 수 있는 적합한 물질로 나타났다. 반면에 CoTMPP를 사용한 미생물연료전지는 연속운전에서 내부 저항의 급격한 증가로 전력밀도가 급격히 감소하였다.

• Membrane and Water Treatment
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• 제4권4호
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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.