• 에너지공학
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• 제23권3호
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• pp.17-20
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• 2014

수중에서 인, 질소의 함유농도는 부유고형물의 농도에 비례하여 증가하기 때문에 부유고형물의 제거는 유기물과 함께 질소, 인을 동시에 제거할 수 있다. 부유고형물은 수중에 미분체를 투입하면 투입된 미분체와 부유고형물 사이에는 반데르발스 힘과 같은 인력이 작용하여 응집이 형성되고 이 응집덩어리는 자성을 띠게 된다. 이와 같은 자성응집덩어리를 자력에 의해 형성된 자성 매트릭스에 직접 부착시켜 분리 제거함으로써 오수를 세정할 수 있다. 본 자료는 자성분리기술과 관련하여 오수 내의 부유고형물의 제거특성에 대한 것을 실험적으로 평가하고 부유물의 제거효율에 대하여 규명하고자 한다.

• Archives of Plastic Surgery
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• 제32권6호
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• pp.723-726
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• 2005

Osmidrosis axillae is a distressing problem characterized by foul odor at the axillae due to excessive apocrine sweat gland secretion. We introduce a new non-surgical method using a specially insulated needle and high frequency electrocoagulator. From September 2001 to January 2005, 52 patients were treated with this procedure for osmidrosis axillae. In authors' procedure, insulated needle which was designed to protect skin and dermal layer was inserted into the deep dermis of axilla area and apocrine sweat glands were removed by electrocoagulation. Fifty two patients were evaluated more than 6 months after surgery. Among these patients, 48 patients received secondary coagulation procedure. After second operation, all patients were satisfied with postoperation results. We conclude that our method has several advantages such as 1) short operation time, 2) no necessity of postoperative immobilization of shoulder joints, 3) no need of hospitalization, 4) minimal scarring and no bleeding, 5) prevention of skin necrosis, 6) a safer operative method for recurred cases as a secondary method.

• Environmental Engineering Research
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• 제22권2호
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• pp.141-148
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• 2017

Globalization, industrialization, mining, and uncontrolled population growth have fostered a shortage of potable water. Therefore, it has become imperative to understand an effective and reasonable water purification technique. A renewed interest in electrocoagulation (EC) has been spurred by the search for reliable, cost-effective, water-treatment processes. This paper has elucidated a technical approach for getting rid of heavy metals and total suspended solids (TSS) from synthetic water using an aluminum electrode. The effect of operational parameters, such as current density, inter-electrode distance, operating time, and pH, were studied and evaluated for maximum efficiency. This study corroborates the correlation between current density and removal efficiency. Neutral pH and a low electrode gap have been found to aid the efficacy of the EC setup. The outcome indicates that a maximum TSS removal efficiency of 76.6% occurred at a current density of $5.3mA/cm^2$ during a contact time of 30 min. In the case of heavy metals remediation, 40 min of process time exhibited extremely reduced rates of 99%, 59.2%, and 82.1%, for Cu, Cr, and Zn, respectively. Moreover, kinetic study has also demonstrated that pollutants removal follows first-and second-order model with current density and EC time being dependent.

• Environmental Engineering Research
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• 제24권2호
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• pp.339-346
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• 2019

In this research, applicability of electrochemical technology in removing nitrogenous compounds from solid waste landfill leachate was examined. Novel cathode material was developed at laboratory by introducing a Cu layer on Al substrate (Cu/Al). Al and mild steel (MS) anodes were investigated for the efficiency in removing nitrogenous compounds from actual leachate samples collected from two open dump sites. Al anode showed better performances due to the effect of better electrocoagulation at Al surface compared to that at MS anode surface. Efficiency studies were carried out at a current density of $20mA/cm^2$ and at reaction duration of 6 h. Efficiency of removing nitrate-N using Al anode and developed Cu/Al cathode was around 90%. However, for raw leachate, total nitrogen (TN) removal efficiency was only around 30%. This is due to low ammonium-N removal as a result of low oxidation ability of Al. In addition to the removal of nitrogenous compounds, reactor showed about 30% removal of total organic carbon. Subsequently, raw leachate was diluted four times, to simulate pre-treated leachate. The diluted leachate was treated and around 88% removal of TN was achieved. Therefore, it can be said that the reactor would be good as a secondary or tertiary treatment step in a leachate treatment plant.

• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.21-32
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• 2021

This study reports for the first time the application of electrocoagulation (EC) from laboratory to pilot scales for the treatment of printing wastewater, a hazardous waste whose treatment and disposal are strictly regulated. The wastewater was taken from three real printing companies with strongly varying characteristics. The treatment process was performed in the laboratory for operational optimization and then applied in the pilot scale. The weight loss of the electrode and the generation of sludge at both scales were compared. The results show that the raw wastewater should be diluted before EC treatment if its COD is higher than about 10,000 mg/L. Pilot scale removal efficiencies of COD and color were slightly lower compared to those obtained from the laboratory scale. At pilot scale, the effluent CODs removal efficiency was 81.9 - 88.9% (final concentration of 448 - 992 mg/L) and color removal efficiency was 95.8 - 98.6% (final level of 89 - 202 Pt-Co) which proved the feasibility of EC treatment as an effective pre-treatment method for printing wastewater as well as other high colored and hard-biodegradable wastewaters.

• 상하수도학회지
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• 제31권4호
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• pp.321-328
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• 2017

Recently EC-MBR (Elctrocoagulation - Membrane Bio Reactor) has been suggested as one of alternative processes to overcome membrane fouling problems. Most important operational parameters in the EC-MBR are known to current density and contact time. Their effect on membrane filtration performances has been reported well, however, quantitative interrelationship between both parameters not been investigated yet. The purpose of this study is to give a kinetic model suggesting the current density and the contact time required to reduce the membrane fouling. The 4 different set of current densities (2.5, 6, 12 and $24A/m^2$) and contact times (0, 2, 6 and 12 hr) were selected as operational parameters. After each electro-coagulation under the 16 different conditions, a series of membrane filtration was carried out. The membrane fouling decreased as the current density and contact time increased, Total fouling resistances under different conditions, $R_t(=R_c+R_f)$ were calculated and compared to those of the controls ($R_0$), which were calculated from the data of experiments without electro-coagulation. A kinetic approach for the fouling reduction rate ($R_t/R_0$) was carried out and the equation ${\rho}^{0.46}_it=7.0$ was obtained, which means that the product of current density and the contact time needed to reduce the fouling in certain amounts (in this study, 10% of fouling reduction) is always constant.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제25권4호
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• pp.367-370
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• 1999

While oral and maxillofacial surgery such as orthognathic surgery, TMJ surgery is in progress, there always exists a risk of bleeding from maxillary artery, and this perplexes the surgeon in operation. In case of massive bleeding, it is mostly very difficult or even impossible to take an immediate action in order to stop bleeding. Even when hemostasis is possible by applying such methods as the use of local hemostatics, pressing, electrocoagulation or direct ligation, there is a high risk of secondary bleeding. Therefore, in case there is bleeding from maxillary artery, it is the best to restrain bleeding completely either by the ligation of the artery in bleeding in operation fields or by the ligation of the external carotid artery.

• 한국환경과학회지
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• 제8권4호
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• pp.539-545
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• 1999

Dye wastewater was treated by using an electrochemical oxidation process. Various combinations of electrodes such as carbon, Al and Fe were investigated. In this study, electrode material, electrolyte concentration, electrode distance, current density, and pH value were found to have significant effect on both pollutant removal efficiency and current efficiency in electrochemical oxidation process. After electrolysis for 40min with carbon/Al, it was observed that COD, $T-N, NH_{4}^{+}-N$ and color of treated wastwater were reduced from 580mg/$\ell$ to 145mg/$\ell$, 67.2mg/$\ell$ to 26.8mg/$\ell$, 46.8mg/$\ell$ to 1.4mg/$\ell$, and 4200 Pt-Co units to 336 Pt-Co units, respectively. The optimal conditions of the electrooxidation process to treat the wastewater for this study were found to be such : current density ; 16.67mA/$cm^2$, electrode distance ; 2.5cm, pH value ; 5.0 and carbon/Al electrode.

• 환경위생공학
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• 제19권3호
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• pp.31-39
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• 2004

In order to reduce the pollution load from the livestock farms and to improve the water quality of the effluent in livestock wastewater, the electrolysis system is introduced. For the selection of optimal electrode, various combination of electrodes such as carbon, Al and Fe were examined. In this study, electrode material, electrolyte concentration, electrode distance, current density, and pH value were found to have significant effect on both pollutant removal efficiency and current efficiency in electrochemical oxidation process. After electrolysis for 90 min with carbon/Al, it was observed that COD, T-N, T-P and $NH_4^+-N$ of livestock waste-water were removed with $80\%,\;61\%,\;81\%\;and\;87\%$, respectively.

• Clinical and Experimental Reproductive Medicine
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• 제10권1호
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• pp.1-6
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• 1983

Women were used as their own controls in the comparison of presterilization and poststerilization menstrual patterns. Five parameters were studied: regularity of cycle length, duration and amount of flow and incidence of dysmenorrhea and intermenstrual bleeding. Three parameters in the electrocoagulation group (regularity of cycle length and duration and amount of flow) and one parameter in the tubal ring group (duration of flow) showed significant changes after sterilization. However, by controlling for the effect of previous contraceptive methods used, no significant menstrual pattern changes following sterilization were discerned in either technique group.