Time filter

Source Type

Busan, South Korea

Dong-eui University is one of the leading private university in Busan, a metropolitan city on the southeastern coast of South Korea. The University has 10 colleges, 116 master and doctoral courses in six graduate schools, with 22,992 students and 1,690 faculty and staff members. Dong-eui has gained fame in the fields of oriental medicine and engineering and has built solid reputations in other fields such as management, health science, nursing, and a range of science. Wikipedia.

Tetrapod-shaped ZnO crystals were synthesized by an oxidation process of Zn powder at temperatures over 930 °C in air. The ZnO crystals were formed in an alumina crucible in which metallic Zn powder was put. X-ray diffraction patterns revealed that the tetrapods were ZnO with wurtzite structure. Any impurities including Zn were not detected, indicating that the ZnO crystals were of high quality. As the oxidation temperature increased, the size of tetrapods was getting larger and longer. However at 1100 °C, tetrapod morphology was disappeared and changed to irregular shape. Strong UV emission at 380 nm was observed in the CL spectra taken for the ZnO tetrapods. The increase in the intensity of green emission at 510 nm was also observed with increased oxidation temperature. © 2010 Elsevier Ltd and Techna Group S.r.l.

Han C.-W.,Dong - Eui University
Applied Mathematics and Information Sciences | Year: 2014

In networked control systems, the varying transmission time delay of the transmitting signal is unavoidable. If the varying transmission time delay exceeds the fixed sampling time, the system will be unstable. To solve this problem, in this paper, the logicbased fuzzy neural networks are applied to the prediction of transmission time delay. The predicted time delay is used as a sampling period of the networked control systems. To show the usability of the proposed method, the transmission time delay data are collected from the real system, and these collected data are used to train and test the logic-based fuzzy neural networks. © 2014 NSP Natural Sciences Publishing Cor.

Ga-doped ZnO(GZO) thin films were deposited on the quartz substrate by magnetron sputtering system with growth interruption technique. As the number of interruptions and interruption time increased, the carrier concentration and Hall mobility in GZO films significantly increased. As a result, the resistivity of GZO films decreased. The optical transmittance of GZO films also increased with the number of interruption and interruption time. The transmittance showed over 90% in visual region. Atomic force microscopy measurement showed that the film surface became smoother with an increase of the number of interruption. In addition, the crystalline quality and electrical properties of GZO films were more improved when the growth interruption was employed with a temperature gradient. © 2013 Elsevier B.V.

Kim M.-M.,Dong - Eui University
Skin Research and Technology | Year: 2011

Background: Procyanidins are a subclass of flavonoids and consist of oligomers of catechin that naturally occur in plants and are known to exert many physiological effects, including antioxidant, anti-inflammatory, and enzyme inhibitory effects. These possible inhibitory effects of the procyanidins were known to involve metal chelation, radical trapping, or direct enzyme binding.Purpose: The purpose of this study was to investigate the effect of procyandin oligomers on hair damage induced by oxidative stress.Results: In this study, several methods for evaluating oxidative damage in bleached hair are utilized to analyze the protective effect of procyandin oligomers against oxidative hair damage. It was observed that procyanidin oligomers strongly bind to keratin in hair and inhibit the breakdown of hair caused by oxidative damage in an analysis of hair using electrophoresis, transmission electron microscope, and fluorescence dye.Conclusion: These results confirm that procyanidin oligomers can be applicable as a potential candidate to the development of hair care with protective effect on hair damage. © 2011 John Wiley & Sons A/S.

Lee G.-H.,Dong - Eui University
Ceramics International | Year: 2014

SnO2 nanowires were synthesized by an unique thermal evaporation technique employing solar energy at atmospheric pressure in air. Sunlight was used to create heat, which is referred herein to as solar thermal energy, a clean form of energy. The sunlight was focused onto a small area containing the tin (Sn) powder by using a magnifying lens. The concentrated sunlight created sufficient heat to melt and vaporize the Sn powder. Furthermore, the Sn vapor was made to react with oxygen in air to form tin oxide (SnO2) product. The product was confirmed to consist of high purity SnO2 nanowires. The SnO2 nanowires was obtained within just several seconds by the solar thermal evaporation technique. The SnO2 nanowires were about several tens of nanometers in diameter and a few tens of micrometers in length. The ultraviolet (UV) emission at 355 nm as well as a visible emission at around 580 nm was observed in the room temperature cathodoluminescence (CL) spectrum, which confirms the high quality of the SnO2 nanowires. These results establish a novel rapid synthesis process for the formation of SnO2 nanowires. © 2014 Elsevier Ltd and Techna Group S.r.l.

Discover hidden collaborations