• 한국환경과학회지
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• 제7권5호
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• pp.697-705
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• 1998

$Pb^{2+}$ removal capacity and initial $Pb^{2+}$ removal rate were compared between non-biomaterials (granular activated carbon, powdered activated carbon, ion exchange resin, zeolite) and biomaterials (activated sludge, Aureobasidium pullulans, Saccharomyces cerevisiae). The $Pb^{2+}$ removal capacity of biomaterials were greater than that of non-biomaterials, generally. The $Pb^{2+}$ removal capacities of non-biomaterials and biomaterials were shown on the order of ion exchange resin ＞ zeolite ＞ granular activated carbon ＞ powdered activated carbon and A. pullulans ＞ S. cerevisiae ＞ activated sludge, respectively. In the initial $Pb^{2+}$ removal rate, the non-biomaterials showed powdered activated carbon ＞ granular activated carbon ＞ zeolite ＞ ion exchange resin and the biomaterials showed A. pullulans ＞ activated sludge ＞ S. cerevisiae. Comparing the $Pb^{2+}$ removal capacity and initial $Pb^{2+}$ removal rate of activated sludge with those of other non-biomaterials and biomaterials, activated sludge may have an availability on the removal of heavy metal ions by the economical and pratical aspects.

• 한국세라믹학회지
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• 제29권5호
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• pp.335-340
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• 1992

Undoped PbTiO3 ceramics was successfully prepared by using sol-gel process, which had not been fabricated due to its microcracks created by anisotropic stress during phase transition from cubic to tetragonal phase. Fabrication of undoped PbTiO3 ceramics via sol-gel processing was very much affected by the PbO content of the samples as well as PbO vapor from sintering atmosphere. Excess PbO was found to promote rapid grain growth in PbTiO3 ceramics. After sintering at 1100$^{\circ}C$ average grain size of PbTiO3 ceramics with excess PbO was about 8 times greater than that of stoichiometric composition, which may be due to PbO liquid phase from excess PbO.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.273-273
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• 2014

Quantum-dot sensitized solar cells (QDSCs) are an emerging class of solar cells owing to their easy fabrication, low cost and material diversity. Despite of the fact that the maximum conversion efficiency of QDSCs is still far less than that of Dye-Sensitized Solar Cells (>12 %), their unique characteristics like Multiple Exciton Generation (MEG), energy band tune-ability and tendency to incorporate multiple co-sensitizers concurrently has made QDs a suitable alternative to expensive dyes for solar cell application. Lead Sulfide (PbS) Quantum dot sensitized solar cells are theoretically proficient enough to have a photo-current density ($J_{sc}$) of $36mA/cm^2$, but practically there are very few reports on photocurrent enhancement in PbS QDSCs. Recently, $Hg^{2+}$ incorporated PbS quantumdots and Cadmium Sulfide (CdS) co-sensitized PbS solarcells are reported to show an improvement in photo-current density ($J_{sc}$). In this study, we explored the efficacy of $In_2S_3$ as an interfacial layer deposited through SILAR process for PbS QDSCs. $In_2S_3$ was chosen as the interfacial layer in order to avoid the usage of hazardous CdS or Mercury (Hg). Herein, the deposition of $In_2S_3$ interfacial layer on $TiO_2$ prior to PbS QDs exhibited a direct enhancement in the photo-current (Isc). Improved photo-absorption as well as interfacial recombination barrier caused by $In_2S_3$ deposition increased the photo-current density ($J_{sc}$) from $13mA/cm^2$ to $15.5mA/cm^2$ for single cycle of $In_2S_3$ deposition. Increase in the number of cycles of $In_2S_3$ deposition was found to deteriorate the photocurrent, however it increased $V_{oc}$ of the device which reached to an optimum value of 2.25% Photo-conversion Efficiency (PCE) for 2 cycles of $In_2S_3$ deposition. Effect of Heat Treatment, Normalized Current Stability, Open Circuit Voltage Decay and Dark IV Characteristics were further measured to reveal the characteristics of device.

• The Korean Journal of Ecology
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• 제16권2호
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• pp.199-208
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• 1993

To estimate the level of the air pollution in Taejon city, the contents of S, Pb and Cd of the leaves of the roadside trees were deterimined. And we analyzed the relationship between the contents of S, Pb and Cd in the leaves of the roadside trees and traffic volume. The ranges of S, Pb and Cd contents in all the samples were 1.82~4.34 mg/g, 1.95~$246.80{\mu}g/g$ and 2.00~$20.50{\mu}g/g$ respectively. Areas with the high contents of S, Pb and Cd in the leaves were the road from Taejon railroad station to the provincial government, West Taejon crossroad, Taehwa-dong, Kasuwon-dong and Yongmun crossroad.

• 한국환경농학회지
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• 제12권3호
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• pp.230-238
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• 1993

폐하수중 합성세제와 중금속을 동시에 효과적으로 처리할 수 있는 다처리기능균주를 개발코자 합성세제 분해능이 우수한 P. fluorescens S1과 Pb축적균인 P. aeruginosa P1을 conjugation 시켜, 합성세제(ABS) 분해능과 Pb 축적능을 동시에 지니는 다처리기능균주 KE101, KE102 및 KE103을 개발하였다. 개발된 다처리기능균주는 Pb축적균인 P. aeruginosa P1 Plasmid가 합성세제 분해균인 P. fluorescens S1 세포내로 전달되었음을 확인하였다. 개발균주의 기질단독처리능력을 조사한 결과는 다음과 같다. 합성세제(ABS)만 단독처리했을 경우 개발균주의 합성세제(ABS) 분해능력은 합성세제 분해 원균주에 비하여 약간 감소하였으나 Pb축적 원균주의 합성세제(ABS) 분해능력에 비하여는 훨씬 증가되었다. Pb만 단독처리했을 경우 개발균주의 Pb처리능력은 Pb축적 원균주에 비하여 감소하였으나 합성세제 분해원균주의 Pb처리능력에 비하여 월등히 증가되었다. 개발균주의 기질혼합 처리능력을 조사한 결과는 다음과 같다. 합성세제(ABS)와 Pb를 혼합처리했을 경우 개발균주 KE101의 합성세제(ABS) 분해능력은 합성세제(ABS)만 단독처리했을 경우에 비하여 악 30%정도 감소되었으며, Pb처리능력은 Pb만 단독처리했을 경우와 비슷하였다. 그리고 개발균주 KE102의 합성세제(ABS)와 Pb를 혼합처리했을 경우의 합성세제(ABS) 분해능력은 합성세제(ABS)만 단독처리했을 경우에 비하여 약 20% 감소되었으나, Pb처리능력은 Pb만 단독처리했을 경우에 비하여 약 25% 증가하였다. 따라서 개발균주 KE101 및 KE102 strain은 원균주의 각 기질처리능력에 비하여는 약간 떨어겼으나 합성세제(ABS)와 중금속의 일종인 Pb를 동시에 효과적으로 처리할 수 있는 능력을 지니고 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.413-413
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• 2012

Lead sulfide (PbS) Colloidal quantum dots (CQDs) are promising material for the photovoltaic device due to its various outstanding properties such as tunable band-gap, solution processability, and infrared absorption. More importantly, PbS CQDs have large exciton Bohr radius of 20 nm due to the uniquely large dielectric constants that result in the strong quantum confinement. To exploit desirable properties in photovoltaic device, it is essential to fabricate a device exhibiting stable performance. Unfortunately, the performance of PbS NQDs based Schottky solar cell is considerably degraded according to the exposure in the air. The air-exposed degradation originates on the oxidation of interface between PbS NQDS layer and metal electrode. Therefore, it is necessary to enhance the stability of Schottky junction device by inserting a passivation layer. We investigate the effect of insertion of passivation layer on the performance of Schottky junction solar cells using PbS NQDs with band-gap of 1.3 eV. Schottky solar cell is the simple photovoltaic device with junction between semiconducting layer and metal electrode which a significant built-in-potential is established due to the workfunction difference between two materials. Although the device without passivation layer significantly degraded in several hours, considerable enhancement of stability can be obtained by inserting the very thin LiF layer (<1 nm) as a passivation layer. In this study, LiF layer is inserted between PbS NQDs layer and metal as an interface passivation layer. From the results, we can conclude that employment of very thin LiF layer is effective to enhance the stability of Schottky junction solar cells. We believe that this passivation layer is applicable not only to the PbS NQDs based solar cell, but also the various NQDs materials in order to enhance the stability of the device.

• 유통과학연구
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• 제9권4호
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• pp.83-91
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• 2011

유통산업의 세계화와 경쟁격화로 유통업체 상표(Private Brand: PB)의 중요성이 부각되면서 유통업체 상표의 구매의도에 영향을 미치는 다양한 선행요인들을 밝히는 연구가 진행되고 있다. 이러한 흐름에 맞춰 본 연구의 목적은 첫째, 유통업체의 이미지가 PB제품을 구매하고자 하는 소비자 태도에 어떠한 영향을 미치는지 확인하였다. 둘째, 소비자의 직업에 따라 PB제품에 대한 지각된 품질에 차이는 어떠한지 확인하였다. 셋째, PB제품을 구매하는 소비자의 직업에 따라 만족도에 차이가 있는지를 살펴보았다. 연구결과를 살펴보면, 첫째, 유통업체의 이미지를 확인하고자 요인분석 결과 윤리성, 신뢰성, 안정성 요인으로 확인되었다. 이러한 요인이 브랜드태도에 미치는 영향을 분석한 결과 윤리성과 안정성은 영향을 미치는 것으로 확인되었다. 그러나 신뢰성은 PB 브랜드태도에 영향을 미치지 않는 것으로 확인되었다. 둘째, 유통업체의 기업이미지가 PB제품에 대한 제품태도에 미치는 영향을 조사한 결과 안정성은 PB 제품태도에 영향을 미쳤으나 윤리성과 신뢰성은 PB 제품태도에 영향을 미치지 않는 것으로 확인되었다. 셋째, 유통업체의 기업이미지가 PB제품에 대한 구매의도에 대한 영향에서는 윤리성은 구매의도에 영향을 미치는 것으로 나타났다. 그러나 신뢰성과 안정성은 영향을 미치지 않는 것으로 나타났다. 넷째, 소비자의 직업에 따른 PB제품의 지각된 품질에 차이가 있는지 확인한 결과 유통업체를 가장 활발하게 이용하는 주부가 가장 높게 나타났으며, 다음으로는 대학생 그리고 직장인 순으로 확인되었다. 다섯째, 소비자의 직업에 따라 PB제품에 대한 만족도를 확인한 결과, PB제품에 대한 만족도에는 유의미한 차이가 나타나지 않았다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.695-696
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• 2012

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.29-30
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• 2000

CaS:Pb thin film used as phosphor layer in electroluminescent devices were deposited by an atomic layer deposition (ALD). The photoluminescence emission and excitation spectra were measured at 5 and 300K for the $CaS:Pb^{2+}$ phosphors with different Pb concentration from 0.001 at.% to 0.648 at.%. The emission spectra of these samples were characterized as UV emission and blue emission with the center of peak around 360 and 425nm, respectively. The UV emission was dominant at the low $Pb^{2+}$ concentration of 0.001 at%, whereas with increase of Pb concentration, the blue emission became a major component and to longer wavelength.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.146-146
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• 2003

If rare earth ions could be activated by electrical means after introducing into an appropriate semiconductor host, it might be possible to achieve the electrically-driven optical amplifier. Futhermore, some groups report that rare earth doped semiconductor nanoparticls show the sensitized emission. In this study, we try to prepare the Er/PbS nanoparticles encaupsulated by phenyl modified silica shell via sol-gel process. Er/PbS nanoparticles were characterized by UV-vis absorption, XRD, FT-IR and TEM etc. Finally we will present the luminescence properties of Er doped PbS nanoencapsulation.