Pure SnO2 has proven very difficult to densify. This poor densification can be useful for the fabrication of SnO2 with a porous microstructure, which is used in electronic devices such as gas sensors. Most electronic devices based on SnO2 have a porous microstructure, with a porosity of > 40%. In pure SnO2, a high sintering temperature of approximately 1300°C is required to obtain > 40% porosity. In an attempt to reduce the required sintering temperature, the present study investigated the low-temperature sinterability of a current system. With the addition of TiO2, the compositions of the samples were Sn1-xTixO2-CoO(0.3wt%)-CuO(2wt%) in the range of x ≤ 0.04. Compared to the samples without added TiO2, densification was shown to be improved when the samples were sintered at 950°C. The dominant mass transport mechanism appears to be grain-boundary diffusion during heat treatment at 950°C.
Based on the Stereotype Content Model and the credibility and persuasion literature, this study examines the influence of COO on advertising claim credibility and purchase intentions. A set of hypotheses were developed and tested with an experimental design on a British sample of consumers.
In this research, we investigate the influence of Chinese consumers’ generation on the perception of “Made in China” luxury. This issue is of utmost importance for the Chinese government as Chinese consumers have now become the first luxury consumers in the world while China remains a non-legitimate dwarf in luxury manufacturing. To bridge this gap, we carried a quantitative survey involving 300 Chinese luxury consumers and tested the effect of consumers’ age on Chinese luxury products perceived luxury. Potential mediators are considered in our analyses, including consumers’ ethnocentrism and innovativeness, materialism, and cultural orientations (i.e., preference for individualism and tradition). The data are currently being collected. Our results will be discussed at the 2023 Global Marketing Conference in Seoul if this research is selected for presentation. They should help position current and future “Made in China” luxury brands and target Chinese luxury consumers.
Transition metal oxides formed by a single or heterogeneous combination of transition metal ions and oxygen ions have various types of crystal structures, which can be classified as layered structures and non-layered structures. With non-layered structures, it is difficult to realize a two-dimensional structure using conventional synthesis methods. In this study, we report the synthesis of cobalt oxide into wafer-scale nanosheets using a surfactant-assisted method. A monolayer of ionized surfactant at the water-air interface acts as a flexible template for direct cobalt oxide crystallization below. The nanosheets synthesized on the water surface can be easily transferred to an arbitrary substrate. In addition, the synthesizing morphological and crystal structures of the nanosheets were analyzed according to the reaction temperatures. The electrochemical properties of the synthesized nanosheets were also measured at each temperature. The nanosheets synthesized at 70 °C exhibited higher catalytic properties for the oxygen evolution reaction than those synthesized at other temperatures. This work suggests the possibility of changing material performance by adjusting synthesis temperature when synthesizing 2D nanomaterials using a wide range of functional oxides, resulting in improved physical properties.
4(5)-methylimidazole (4(5)-MI) is carcinogenic, nitrogen-containing compound, mainly found during the manufacturing of caramel coloring. Hence, presence of 4(5)-MI is well-known in any food products with addition of caramel coloring for desirable sensory characteristics, such as cookies. Limited work has been conducted to develop suitable analytical method and to investigate effect of caramel coloring in cookies. This study aimed at developing the analytical method for quantification of 4(5)-MI and confirming influence of caramel coloring on level of 4(5)-Mi in cookies. Gas chromatography-mass spectrometry (GC-MS) was utilized for qualification and quantification of 4(5)-MI. Sample preparation procedure specialized in bakery products was fully developed in this study. The concentration of 4(5)-MI in 15 commercial cookies and biscuits ranged from 71.5 to 1254.8 ng/g. Correlation equation (y = 706.42x + 21.792) was obtained to estimate effect of caramel colorant on level of 4(5)-MI in cookies. Further, analytical method developed and results of correlation equation can be utilized in future studies on reduction of 4(5)-MI in many food.
SnO2-CoO/carbon-coated CoO core/shell nanowire composites were synthesized by using electrospinning and hydrothermal methods. In order to obtain SnO2-CoO/carbon-coated CoO core/shell nanowire composites, SnO2-Co3O4 nanowire composites and SnO2-Co3O4/polygonal Co3O4 core/shell nanowire composites are also synthesized. To demonstrate their structural, chemical bonding, and morphological properties, field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were carried out. These results indicated that the morphologies and structures of the samples were changed from SnO2-Co3O4 nanowires having cylindrical structures to SnO2-Co3O4/Co3O4 core/shell nanowires having polygonal structures after a hydrothermal process. At last, SnO2-CoO/carbon-coated CoO core/shell nanowire composites having irregular and high surface area are formed after carbon coating using a polypyrrole (PPy). Also, there occur phases transformation of cobalt phases from Co3O4 to CoO during carbon coating using a PPy under a argon atmosphere.
강유전체 전계효과를 관찰하기 위해 LaCoO3/Pb(Zr, Ti)O3(La, Sr)CoO3 다층구조를 LcOo3가 기판 위에 pulsed laser deposition(PLD)법으로 에피택셜하게 성장시켰다. 이러한 다층구조에서는 전도성 채널층으로 Si대신 반도성 LaCoO3가 사용 되었다. LaCoO3(LCO)의 비저항은 산소 분위기에 의하여 변화되었는데 특히 증착시 산소 분위기에 의존함을 보였다. LCO의 비저항은 0.1-100Ωcm범위에서 변화되었다. LCO층에 유도되는 강유전체 전계효과는 Pb(Zr, Ti)O3(PZT)의 분극 상태에 따른 LCO의 저항 변화를 측정함으로써 관찰되었는데 1020Å 두께를 가진 LCO층에서는 4%의 저항 변화를 얻었으며 680Å의 LCO에서는 9%의 증가된 저항 변화를 얻었다. DC 바이어스(-5V)를 가한 후에는 저항 변화가 45%까지 증가하였다. 이러한 결과는 적당한 비저항을 갖는 LCO를 사용한 LCO/PZT/LSCO다층구조가 강유전체 전계효과 트랜지스터로 사용될 수 있다는 가능성을 제시하고 있다.