• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.511-512
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.171-172
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• 2006

• Journal of the Korean Society of Costume
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• v.54 no.7
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• pp.55-62
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• 2004

Research into the ancient dyeing and weaving culture is of critical importance to the fact that they constitute an integral part of the Korean costume. Due to the absence of the originals reflecting ancient costume cultures, it is difficult to figure out what the dyeing and weaving culture was like in ancient times. Because of limited visual materials available from the wall paintings of ancient tombs, studies conducted so far concerning the costume culture for the Goguryeo have focused on visual elements such as shape, structure, and type. As a result, research into ancient Korean dyeing and weaving cultures hasn't been properly made. Thanks to the presence of both some dyeing fabric originals from Goguryeo's neighboring countries and some visual materials like the wall paintings of the Goguryeo, it may be possible to obtain some clues to the dyeing and weaving culture. The dotted Pattern costumes were selected such as Muyongchong, No. 1 Jangcheon Tomb, Gakjeochong, Samsilchong, Ssangyeongchong, Susanri Tomb. According to a book titled ‘Hanwon’, the Goguryeo people manufactured fabrics in such a way that resist-dyed spots produced elaborate patterns over the purple fabric. It can be safely said that such dot patterns were produced by means of dyeing rather than weaving, because identical patterns aren’t well produced by means of painting and embroidery. Considering Goguryeo’s natural features, the dot patterns mentioned in historical literatures are thought to have been produced using animal’s skin. However, there is highest possibility that the dot Patterns were Produced using tie-resist dyeing or wax-resist dyeing techniques. With respect to the dyeing and weaving culture for the Goguryeo, one must refer to neighboring countries’ dyeing and weaving environments, given that the Goguryeo had engaged substantial cultural exchanges with China.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.457-465
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• 2014

Size-controlled lead sulfide (PbS) quantum dots were synthesized by the typical hot injection method using oleic acid (OA) as the stabilizing agent. Subsequently, the ligand exchange reaction between OA and thioacetic acid (TAA) was employed to obtain TAA-capped PbS quantum dots (PbS-TAA QDs). The condensation reaction of the TAA ligands on the surfaces of the QDs enhanced the conductivity of the PbS-TAA QDs thin films by about 2-4 orders of magnitude, as compared with that of the PbS-OA QDs thin films. The electron transport mechanism of the PbS-TAA QDs thin films was investigated by current-voltage (I-V) measurements at different temperatures in the range of 293 K-473 K. We found that the charge transport was due to sequential tunneling of charge carriers via the QDs, resulting in the thermally activated hopping process of Arrhenius behavior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.922-925
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• 2003

The interest of self-organization materials that have uniform and regular structure in nano scale has been grown due to their utilization in various fields of nanotechnology. An attractive candidate among these materials is anodic aluminum oxide film, which are formed by anodization of aluminum in an appropriate acid solution. The anodic aluminum oxide film has a highly ordered porous structure with very uniform and nearly parallel pores that can be organized in an almost precise close-packed hexagonal structure. In this study, we attempt to make Au dot arrays, which were fabricated using anodic aluminum oxide film as an evaporation mask. The Au dot arrays have a uniform sized dots and spacing to its neighbors and the average diameter of Au dots is about 60 nm corresponding to them of the mask.

• Carbon letters
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• v.21
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• pp.8-15
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• 2017

The thermoelectric Seebeck and Peltier effects of a single walled carbon nanotube (SWCNT) quantum dot nanodevice are investigated, taking into consideration a certain value of applied tensile strain and induced ac-field with frequency in the terahertz (THz) range. This device is modeled as a SWCNT quantum dot connected to metallic leads. These two metallic leads operate as a source and a drain. In this three-terminal device, the conducting substance is the gate electrode. Another metallic gate is used to govern the electrostatics and the switching of the carbon nanotube channel. The substances at the carbon nanotube quantum dot/metal contact are controlled by the back gate. Results show that both the Seebeck and Peltier coefficients have random oscillation as a function of gate voltage in the Coulomb blockade regime for all types of SWCNT quantum dots. Also, the values of both the Seebeck and Peltier coefficients are enhanced, mainly due to the induced tensile strain. Results show that the three types of SWCNT quantum dot are good thermoelectric nanodevices for energy harvesting (Seebeck effect) and good coolers for nanoelectronic devices (Peltier effect).

• Journal of Hydrogen and New Energy
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• v.32 no.6
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• pp.663-668
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• 2021

For the development of highly efficient quantum dot-sensitized solar cells (QDSCs), it is important to enhance the electrocatalytic activity of the counter electrodes (CEs). Herein, a fabrication process of Cu₂S CEs are optimized for the development highly efficient QDSCs. The surface of brass film is treated with HCl solution to prepare the Cu₂S CEs, and the concentraion as well as the temperature of HCl solution are controlled. It is found that the uniformity for the thickness of prepared Cu₂S CEs is enhanced when the diluted HCl solution is used, compared to the HCl solution of standard concentration. In addition, the electrocatalytic activity of the Cu₂S CEs is also increased with the modificed process, which is confirmed by impedance data and Tafel polarization curves. As a result, the photoconversion efficiency of QDSCs is improved from 4.49% up to 5.73%, when the concentraion and temperature of the HCl treatment are efficiently optimized.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.417-417
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• 2012

For desired optical properties of QDs, it is very important to reduce the presence of defects on their surfaces. Passivation of surface defects using larger band gap materials is the most effective way. Some groups successfully synthesized Cd based multi-shell structured quantum dots and improved its optical properties. However, its productivity has limit because of the amounts of glass ware and space. In this research, we try to synthesize Cd based multi-shell structured nanocrystal quantum dots to overcome demerits of conventional batch synthetic method. This reactor composed pump, SUS reaction part (3.2 mm stainless steel and furnace) and batch mixer. We successively synthesized CdSe/CdS/ZnS quantum dot at this reactor in one step.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.6-9
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• 1997

Black dot root rot of eggplant was first found in vinyl-housed fields of Yeoju area in Korea in May, 1993. The causal fungus of the disease was identified as Colletotrichum coccodes (Wallr.) Hughes based on the morphological and cultural characteristics. Pathogenicity tests revealed that isolates of the fungus were responsible for the disease.

• Journal of Powder Materials
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• v.26 no.1
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• pp.45-48
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• 2019

Quantum dots (QDs) are an attractive material for application in solar energy conversion devices because of their unique properties including facile band-gap tuning, a high-absorption coefficient, low-cost processing, and the potential multiple exciton generation effect. Recently, highly efficient quantum dot-sensitized solar cells (QDSCs) have been developed based on CdSe, PbS, CdS, and Cu-In-Se QDs. However, for the commercialization and wide application of these QDSCs, replacing the conventional rigid glass substrates with flexible substrates is required. Here, we demonstrate flexible CISe QDSCs based on vertically aligned $TiO_2$ nanotube (NT) electrodes. The highly uniform $TiO_2$ NT electrodes are prepared by two-step anodic oxidation. Using these flexible photoanodes and semi-transparent Pt counter electrodes, we fabricate the QDSCs and examine their photovoltaic properties. In particular, photovoltaic performances are optimized by controlling the nanostructure of $TiO_2$ NT electrodes.