• Journal of Environmental Science International
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• v.21 no.11
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• pp.1371-1377
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• 2012

The simulated dyes solution containing Basic Red 46(BR 46), Yellow 21(Y 21), and Maxilon Blue 30(MB 30) were electrochemically oxidized using carbon fiber as an anode. The electrolyses were performed in a electrolytic flow cell constructed by Vycor glass tube. The carbon fiber was positioned in the inside of Vycor glass tube and platinum wire coiled around outside of tube as a cathode. Several operating variables, such as current, time, pH and flow rate of solution were studied. Increasing current density would lead to a corresponding increase in the dye removal efficiency 99.2 % at a 200 mA. The electrolyses time could also improve and removal efficiency was about 99 % after 1.5 hours of electrolyses. The removal efficiency was increased with the increase of flow rate of solution and optimum flow rate was 5 mL/min. THe pHs of solution affect the removal efficiency. The removal efficiency was decreased with the increase of pH of solution and optimum pH was 5.05 (0.1 M $KNO_3$).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.241-241
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• 2010

Recently high and persistent spontaneous buildup of a surface potential (SP) upon vacuum deposition of tris (8-hydroxyquinolinato) aluminum (III) ($Alq_3$), which is widely used for organic light emitting devices. The removal of the giant surface potential by visible light irradiation has also been reported. In this study, we coated $Alq_3$ on the FTO substrate and raise the capacity for absorbing sun light. The $Alq_3$ which is green light emitting diode emits light at wavelengths between 500 and 550nm. If we apply one's FTO/$Alq_3$ substrate in one's DSSC, we could get higher energy conversion efficiency because the N719 dye that we used for fabricating the DSSC emits light just at near 540nm. The energy conversion efficiency of approximately 4.8 % at the condition of irradiation of AM 1.5 (100 mW/$cm^2$) simulated sunlight, and the $J_{sc}$ is 12.0 mA/$cm^2$, $V_{oc}$ is 0.71 V, FF is 0.56, respectively.

• Journal of the Korean Ceramic Society
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• v.51 no.3
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• pp.139-144
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• 2014

Activated carbon fiber (ACF) was modified with MnS nanoparticles to prepare MnS-ACF, and it was employed for preparation of MnS-$ACF/TiO_2$ composites with titanium (IV) n-butoxide (TNB). The properties of MnS-$ACF/TiO_2$ composites were characterized by XRD, SEM, and EDX. EDX results showed the presence of C, O, and Ti as major elements and traces of the metal elements Mn and S. The photocatlytic activity was evaluated by degradation of methyl blue (MB) and methyl orange (MO) dye. The results demonstrated that as-prepared samples could effectively photodegrade MB and MO under UV irradiation. Subsequently, the decomposition of MB solution showed the combined effects of adsorptions by ACF and enhanced photocatalytic effect by $TiO_2$. Finally, the photocatalytic effect increased due to photo-induced-electron absorption effect by ACF and electron trap effect by comodified MnS nanoparticles.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.55.1-55.1
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• 2011

Dye-sensitized solar cell(DSSC) have been considered one of the promising alternatives to conventional solar cells, because of their low cost, easy fabrication and relatively high energy conversion efficiency. However, although the cell offers reasonable efficiency at least 11%, the use of a liquid electrolyte placed technological challenges for achieving the desired durability and operational stability of the cell. In order to prevent or reduce electrolyte leakage considerable efforts have been made, such as p-type semiconductor or organic hole-transport material that better mechanical properties and simple fabrication processes. In this work, we synthesized solid-state electrolyte containing LiI and KI metal salt with starting materials of poly ethylene oxide to substitute liquid electrolyte enhance the ionic conductivity and solar conversion efficiency. Li+ leads to faster diffusion and higher efficiency and K+ leading to higher ionic conductivity. The efficiency of poly ethylene oxide/LiI system electrolyte is 1.47% and poly ethylene oxide/potassium electrolyte is 1.21%. An efficiency of 3.24% is achieved using solid-state electrolyte containing LiI and KI concentrations. The increased solar conversion efficiency is attributed to decreased crystallinity in the polymer that leads to enhanced charge transfer.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.201-207
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• 2016

The hazards associated with the polycyclic aromatic hydrocarbons (PAHs) are known to be recalcitrant by their structure, but white rot fungi are capable of degrading recalcitrant organic compounds. Phlebia brevispora KUC9045 isolated from Korea was investigated its efficiency of degradation of four PAHs, such as phenanthrene, anthracne, fluoranthene, and pyrene. And the species secreted extracellular laccase and MnP (Manganese dependent peroxidase) during degradation. P. brevispora KUC9045 demonstrated effective degradation rates of phenanthrene (66.3%), anthracene (67.4%), fluoranthene (61.6%), and pyrene (63.3%), respectively. For enhancement of degradation rates of PAHs by the species, Remazol Brilliant Blue R (RBBR) was preferentially supplemented to induce ligninolytic enzymes. The biodegradation rates of the three PAHs including phenanthrene, fluoranthene, and pyrene were improved as higher concentration of Remazol Brilliant Blue R was supplemented. However, anthracene was degraded with the highest rate among four PAHs after two weeks of the incubation without RBBR addition. According to the previous study, RBBR can be clearly decolorized by P. brevispora KUC9045. Hence, the present study demonstrates simultaneous degradation of dye and PAHs by the white rot fungus. And it is considered that the ligninolytic enzymes are closely related with the degradation. In addition, it indicated that dye waste water might be used to induce ligninolytic enzymes for effective degradation of PAHs.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.251-262
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• 2014

최근 유기 발광 다이오드(Organic Light Emitting Diodes; OLED)가 각광받고 있어 이를 개발하기 위한 좀 더 효율적이고 실용적인 OLED 구조의 예측이 필요해지고 있다. 본 연구는 가장 기초적인 OLED dye의 형태인 $Ru(bpy){_3}^{2+}$와 그와 유사한 구조의 발광 물질이 전기화학발광(ECL) 현상을 통해 방출하는 빛의 특성을 계산하는 것을 목적으로 한다. EDISON 화학 서버의 GAMESS 프로그램을 사용하여 $Ru(bpy){_3}^{2+}$와 유도체들의 바닥상태(ground state)와 첫 번째 들뜬 상태(first excited state)를 계산하였다. Basis set으로는 MINI와 3-21G 혹은 SBKJC를 사용하였다. 들뜬 상태 계산은 configuration interaction with single excitation(CIS)을 이용하여 단일항(singlet)과 삼중항(triplet) 상태에서 바닥과 들뜬 상태의 최적 구조에 대한 계산을 수행하였다. 다양한 방법으로 방출 파장을 계산한 결과를 바탕으로 $Ru(bpy){_3}^{2+}$와 다양한 유도체들의 에너지 계산에 어떤 방법이 효율적으로 적용될 수 있을지 탐색하였다. 같은 계산방법들이 중심 금속이 이리듐(Ir)인 분자에도 적용이 될 수 있을지 알아보기 위해 $lr(mppy)_3$에도 적용하였다. 본 연구를 통하여 얻어진 방식은 시간을 절약하고 더 효율적인 $Ru(bpy){_3}^{2+}$ 유도체 계산에도 사용할 수 있을 것이다.

• Carbon letters
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• v.11 no.4
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• pp.332-335
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• 2010

The photodegradation of the model compounds Quinol, an aromatic organic compound and Acid blue FFS, an acid dye of chemical class Triphenylmethane was studied by using illumination with UV lamp of light intensity 250W. $TiO_2$ and $TiO_2$ doped with Boron and Nitrogen was used as catalyst. The sol-gel method was followed with titanium isopropoxide as precursor and doping was done using Boron and Nitrogen. In photocatalytic degradation, $TiO_2$ and doped $TiO_2$ dosage, UV illumination time and initial concentration of the compounds were changed and examined in order to determine the optimal experimental conditions. Operational time was optimized for 360 min. The optimum dosage of $TiO_2$ and BN doped $TiO_2$ was obtained to be 2 $mgL^{-1}$ and 2.5 $mgL^{-1}$ respectively. Maximum degradation % for quinol and Blue FFS acid dye was 78 and 95 respectively, at the optimum dosage of BN-doped $TiO_2$ catalyst. It was 10 and 4% higher than when undoped $TiO_2$ catalyst was used.

• Journal of Environmental Health Sciences
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• v.19 no.3
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• pp.29-35
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• 1993

This study was performed to obtain optimal conditions for reduction of color in dye wastewaters using coagulation-sedimentation processes with redox reactions. The reduction of color as well as organic matters variation was observed after coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O and NaOCl. Coagulation-redox reaction was done with the dose of Coagulant and oxidant at various pH values. Redox reaction was done through jar-mixing and aeration. The results of study were as follows: 1. In the coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was heigher at pH 3. With variance of dosage of FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was higher at 250 mg/l. When coagulation-sedimentation using FeSO$_4$ $\cdot$ 7H$_2$O 250 mg/l was added at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 47.6%, 21.3% and 22.1%, respectively. 2. When NaOCI was added at level of 100 ppm in raw wastewater at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 30.2%, 5.5% and 6.2%, respectively. 3. After coagulation-sedimentation processes by addition of FeSO$_4$ $\cdot$ 7H$_2$O, when NaOCl was added at level of 250 mg/l in supernant, color reduction was 47.8% in aeration and 37.5% in jar-mixing. 4. Color reduction by aeration was higher than that by jar-mixing.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.83-85
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• 2019

Pseudomonas sp. PAMC 29040 was isolated from a maritime tundra soil in Antarctica for its ability to degrade lignin and subsequently confirmed to be able to depolymerize heterogeneous humic substance (HS), a main component of soil organic matter. The draft genome sequences of PAMC 29040 were analyzed to discover the putative genes for depolymerization of polymeric HS (e.g., dye-decolorizing peroxidase) and catabolic degradation of HS-derived small aromatics (e.g., vanillate O-demethylase). The information on degradative genes will be used to finally propose the HS degradation pathway(s) of soil bacteria inhabiting cold environments.

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• v.5 no.5
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• pp.643-650
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• 2018

A self-powered electrochromic device was fabricated on an indium tin oxide-polyethylene naphthalate flexible substrate using a dye-sensitized solar cell (DSSC) as a self-harvesting source; the electrochromic device was naturally bleached and operated under outdoor light conditions. The color of the organic electrochromic polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, was shifted from pale blue to deep blue with an antimony tin oxide film as a charge-balanced material. Electrochromic performance was enhanced by secondary doping using dimethyl sulfoxide. As a result, the device showed stable switching behavior with a high transmittance change difference of 40% at its specific wavelength of 630 nm for 6 hrs. To improve the efficiency of the solar cell, 1.0 wt.% of Ag NWs in the photoanode was applied to the $TiO_2$ photoanode. It resulted in an efficiency of 3.3%, leading to an operating voltage of 0.7 V under xenon lamp conditions. As a result, we built a standalone self-harvesting electrochromic system with the performance of transmittance switching of 29% at 630 nm, by connecting with two solar cells in a device. Thus, a self-harvesting and flexible device was fabricated to operate automatically under the irradiated/dark conditions.