• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.33-40
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• 2007

We have designed and synthesized three Zn(II)-porphyrin derivatives, such as Zn(II) porphyrin ([G-0]Zn-P1) and aryl ether-typed dendron substituted Zn(II)-porphyrin derivatives ([G-1]Zn-P1 and [G-1]Zn-P-CN1). Their chemical structures were characterized by 1H-NMR, FT-IR, UV-vis absorption, EI-mass, and MALDI-TOF mass spectroscopies. Their electrochemical properties were studied by cyclic voltammetry measurement. These Zn(II)-porphyrin derivatives have been used to fabricate dye-sensitized solar cells (DSSCs) based on solid polymeric electrolytes as dye sensitizers and their device performances were evaluated by comparing with that of a standard Ru(II) complex dye. [G-1]Zn-P-CN1 showed the enhanced power conversion efficiency than those of other porphyrin derivatives, as expected. Short-circuit photocurrent density (Jsc), open-circuit voltage (Voc), fill factor (FF), and power conversion efficiency (η) of solid-typed DSSC for [G-1]Zn-P-CN1 were evaluated to be Jsc = 11.67 mA/cm2, Voc = 0.51 V, FF = 0.46, and η = 2.76%, respectively.

• 대한설비공학회지:설비저널
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• 제33권3호
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• pp.50-57
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• 2004

This article reviews absorption cooling R＆D in Europe from the viewpoint of fundamentals, cycle development and applications. The review contains information on R＆D, predominantly of public projects in the field of sorption cooling. We report on research which is performed in Europe with some stress on Germany. There is progress in fundamentals, thermodynamic cycle design, and also applications. In the fundamentals part the discussion about thermodynamics, working pairs, and heat and mass transfer is reflected. Today's discussion on thermodynamic cycles is not very strong. Main focus is on special solid sorption cycles, compression­sorption hybrids, and open cycles, In the applications part the chilling business is the main issue. Some interest is given to the improvement of efficiency on and the adaptation to low temperature waste heat use, but the stress is on the use of solar energy as heat source. The area of heat pumping for heating purposes is less prominent but not at all negligible. Finally, industrial heat pumping involves the reverse cycle (heat transformer, heat pump type Ⅱ) also, but there is no significant activity.

• 대기
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• 제22권3호
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• pp.367-379
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• 2012

Measurements of $PM_{10}$ mass concentration, aerosol light scattering and absorption coefficients as well as aerosol size distribution were made to characterize the aerosol physical and optical properties at the two Korean WMO/GAW regional stations, Anmyeondo and Gosan. Episodic cases of the severe Asian dust events occurred in spring of 2009-2010 were studied. Results in this study show that the aerosol size distributions and optical properties at both stations are closely associated with the dust source regions and the transport routes. According to the comparison of the $PM_{10}$ mass concentration at both stations, the aerosol concentrations at Anmyeondo are not always higher than those at Gosan although the distance from the dust source region to Anmyeondo is closer than that of Gosan. The result shows that the aerosol concentrations depend on the transport routes of the dust-containing airmass. The range of mass scattering efficiencies at Anmyeon and Gosan was 0.50~1.45 and $0.62{\sim}1.51m^2g^{-1}$, respectively. The mass scattering efficiencies are comparable to those of the previous studies by Clarke et al. (2004) and Lee (2009). It is noted that anthropogenic fine particles scatter more effectively the sunlight than coarse dust particles. Finally, we found that the aerosol size distribution and optical properties at Anmyeondo and Gosan show somewhat different properties although the samples for the same dust_episodic events are compared.

• Korean Chemical Engineering Research
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• 제45권1호
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• pp.81-86
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• 2007

산업 시설에서 발생하는 $SO_2$를 제거하기 위해 중공사막 기-액 접촉기를 사용하고 있다. 본 연구에서는 기-액 접촉기 내의 중공사막에서의 $SO_2$ 흡수거동 대하여 수학적으로 모델링하고, 그 모델을 유한 요소 분석법을 이용하여 모사하였다. $SO_2$의 분리에 영향을 주는 변수인 기체 유량, 분리막의 물질 전달 계수 및 접촉기의 물리적 특성에 따른 $SO_2$의 분리 효율 및 물질 전달 특성을 알아보았다. 기체의 유속 변화에 따른 중공사막을 통한 $SO_2$ 제거 효율 실험값으로부터 분리막의 물질 전달 계수를 추정하였다. 또한 중공사막 설계에 도움이 되는 자료를 계산할 수 있는 방법을 제시하였다.

• 상하수도학회지
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• 제18권5호
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• pp.656-665
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• 2004

An Ozone reaction model combined with CFD(Computational Fluid Dynamics) technique was developed in this research, in the simulation of ozonation, hydrodynamic behavior as well as reaction model is important because ozone is supplied to treated water as gas ozone. In order to evaluate hydrodynamic behavior in an ozone contactor, CFD technique was applied. CFD technique elucidated hydrodynamic behavior in the selected ozone contactor, which consisted of three main chambers. Three back-mixing zones were found in the contactor. The higher velocities of water were observed in the second and third compartments than that in the first compartment. The flow of the opposite direction to the main flow was observed near the water surface. Based on the results of CFD simulation, the ozone contactor was divided into small compartments. Mass balance equations were established were established in each compartment with reaction terms. This reaction model was intended to predict dissolved ozone concentration, especially. We concluded that the model could predict favorably the mass balance of ozone, namely absorption efficiency of gaseous ozone, dissolved ozone concentration and ozone consumption. After establishing the model, we discussed the effect of concentration of gaseous ozone at inlet, temperature and organic compounds on dissolved ozone concentration.

• 한국진공학회지
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• 제5권4호
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• pp.341-347
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• 1996

Spray pyrolysis 방법으로 넓은 면적의 $Cu_2S$/CdS 태양전지를 제작하였다. 제작과정에서 전극형성, CdS spray 온도조건, $Cu_2S$층의 접합 조건등 태양전지의 효율에 영향을 주는 요인을 조사하였다. CdS 박막의 조건은 주사 전자현미경, X-선 회절기, 온도변화에 따른 광흡수 및 관전도 특성등을 통해 결정하였다. 1$\textrm{cm}^2$의 면적의 전지에 air mass 2(AM2)인 75mW/$\textrm{cm}^2$로 빛을 조사했을 때 3.15%의 효율을 얻었다.

• 한국응용과학기술학회지
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• 제19권4호
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• pp.335-338
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• 2002

A new process for polymeric gate insulator in field-effect transistors was proposed. Fourier transform infrared absorption spectra were measured in order to identify ODPA-ODA polyimide. Its breakdown field and electrical conductivity were measured. All-organic thin-film transistors with a stacked-inverted top-contact structure were fabricated to demonstrate that thermally evaporated polyimide films could be used as a gate insulator. As a result, the transistor performances with evaporated polyimide was similar with spin-coated polyimide. It seems that the mass-productive in-situ solution-free processes for all-organic thin-film transistors are possible by using the proposed method without vacuum breaking.

• 한국응용과학기술학회지
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• 제25권2호
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• pp.265-268
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• 2008

Among the efforts to increase the efficiency of organic light-emitting device (OLED), there is a way: doping phosphorescent materials. As a phosphorescent material, complexes of heavy transition metal, platinum, were synthesized. $Cl^-$ ion and phenyl group were used as ancillary ligands with 2-(2-pyridyl)benzimidazole (pbi) as a chromophore. The complexes were analysed by FAB-mass spectrometer and absorption and emission spectra were obtained. A phenyl group was able to shift the emission band of the complex even if it's not a chromorphore.

• 천문학회보
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• 제43권2호
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• pp.51.3-51.3
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• 2018

MBM 110 is one of the molecular clouds at high Galactic latitude discovered by Magnani et al., and is one of a dozen cometary clouds in the Orion-Eridanus superbubble. We have conducted optical photometry and spectroscopy for a comprehensive study of the region. Recently released Gaia DR2 astrometric data as well as WISE mid-infrared data were used for the complete census of member stars. We select 17 member stars with $H{\alpha}$ emission and/or Li absorption. The total mass of stars in the region is only about $16M{\odot}$. We found that the star formation efficiency in the region is less than 5%. We discuss the origin of the cloud and the star formation history in MBM 110.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.226-226
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• 2013

Si is a dominant solar material, which is the second most abundant element in the earth giving a benefit in the aspect in cost with low toxicity. However, the inherent limit of Si has an indirect band gap of 1.1 eV resulting in the limited optical absorption. Therefore, a critical issue has been raised to increase the utilization of the incident light into the Si absorber. The enhancement of light absorption is a crucial to improve the performances and thus relieves the cost burden of Si photovoltaics. For the optical aspect, an efficient design of a front surface, where the incident light comes in, has been intensively investigated to improve the performance of photon absorption. Lambertian light trapping can be attained when the light active surface is ideally rough to increase the optical length by about 50 compared to a planar substrate. This suggests that an efficient design may reduce thickness of the Si absorber from the conventional 100~300 ${\mu}m$ to less than 3 ${\mu}m$. Theoretically, a hole-array structure satisfies an equivalent efficiency of c-Si with only one-twelfth mass and one-sixth thickness. Various approaches have been applied to improve the incident light utilization in a Si absorber using textured structures, periodic gratings, photonic crystals, and nanorod arrays. We have designed hole and pillar structured Si absorbers. Four-different Si absorbers have been simultaneously fabricated on an identical Si wafer with hole arrays or pillar arrays at a fixed depth of 2 ${\mu}m$. We have found that the significant enhanced solar cell performances both for the hole arrayed and pillar arrayed Si absorbers compared to that of a planar Si wafer resulting from the effective improvement in the quantum efficiencies.