N-doped Na2Ti6O13@TiO2 (denoted as N-NTO@TiO2) composites are successfully synthesized using a simple two-step process: 1) ball-milling of TiO2 with Na2CO3 followed by heat treatment at 900oC; 2) mixing of the prepared Na2Ti6O13 with titanium isopropoxide and calcining with urea at 500oC. The prepared composites are characterized using XRD, SEM, TEM, FTIR, and BET. The N-NTO@TiO2 composites exhibit well-defined crystalline and anatase TiO2 with exposed {101} facets on the external surface. Moreover, dopant N atoms are uniformly distributed over a relatively large area in the lattice of the composites. Under visible light irradiation, ~51% of the aqueous methylene blue is photodegraded by N-NTO@TiO2 composites, which is higher than the values shown by other samples because of the coupling effects of the hybridization of NTO and TiO2, N-doping, and presence of anatase TiO2 with exposed {101} facets.

경제 불안정과 고령화, 경쟁격화 및 개인 가치관의 변화 등 사회 문제가 점점 심각해질 가능성이 있다. 이러한 상황에서 이를 해결 가능한 방안 중 하나로써 감성컴퓨팅 관련 연구가 증가하고 있다. 이에 본 연구는 감성컴퓨팅 연구 키워드를 중심으로 국내 및 글로벌 연구의 지식구조와 주요 키워드, 연구생산 현황 및 국가간 협력관계 및 주요 키워드별 네트워크 등을 파악하였다. 이를 위해 전문 학술데이터 베이스(Scopus)로부터 해당 키워드를 중심으로 논문을 검색하였으며, 서지분석과 네트워크 분석을 실시하였다. 중국과 미국이 Affective computing 분야에서 지식생산이 활발하였고, 한국은 약 10% 정도로 저조한 상황이다. 주요 키워드는 Affective computing을 중핵으로 주로 컴퓨팅 처리 및 감성분석, 인식을 분류하는 연구 및 사용자들의 모델링, 심리 분석이 주요 연구 키워드이다. 국가 간 협력구조는 중국과 미국이 가장 큰 클러스터를 형성하고 있고, 그 외에 영국, 독일, 스위스, 스페인, 캐나다 등이 협력을 주도하고 있다. 한국의 연구협력은 다양하지 않고 연구생산도 저조한 결과를 보였다. Affective computing 분야의 연구발전을 위해 미국, 중국 등 주요국과의 연구협력 강화와 연구파트너의 다양화를 위한 시사점을 결론으로 제언하였다.

A facile one-pot wet chemical process to prepare pure anatase TiO2 hollow structures using ammonium hexafluorotitanate as a precursor is developed. By defining the formic acid ratio, we fabricate TiO2 hollow structures containing fluorine on the surface. The TiO2 hollow sphere is composed of an anatase phase containing fluorine by various analytical techniques. A possible formation mechanism for the obtained hollow samples by self-transformation and Ostwald ripening is proposed. The TiO2 hollow structures containing fluorine exhibits 1.2 - 2.7 times higher performance than their counterparts in photocatalytic activity. The enhanced photocatalytic activity of the TiO2 hollow structures is attributed to the combined effects of high crystallinity, specific surface area (62 m2g-1), and the advantage of surface fluorine ions (at 8%) having strong electron-withdrawing ability of the surface ≡ Ti-F groups reduces the recombination of photogenerated electrons and holes.

F-containing TiO2 nanopowders are synthesized using simple wet processes (precipitation-based and hydrothermal) from ammonium hexafluorotitanate (AHFT, (NH4)2TiF6) as a precursor to apply as a photocatalyst for the degradation of rhodamine B (RhB). The surface properties of the prepared samples are evaluated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The results confirm that the synthesized anatase TiO2 has sphere-like shapes, with numerous small nanoparticles containing fluorine on the surface. The photocatalytic activity of F-containing TiO2 compared with F-free TiO2 is characterized by measuring the degradation of RhB using a xenon lamp. The photocatalytic degradation of F-containing TiO2 exhibits improved photocatalytic activity, based on the positive effects of adsorbed F ions on the surface.

In this study, TiO2 powders are synthesized from ammonium hexafluoride titanate (AHFT, (NH4)2TiF6) as a precursor by heat treatment. First, we evaluate the physical properties of AHFT using X-ray diffraction (XRD), particle size analysis (PSA), thermogravimetric analysis (TGA), and field-emission scanning electron microscopy (FESEM). Then, to prepare the TiO2 powders, is heat-treated at 300-1300oC for 1 h. The ratio of anatase to rutile phase in TiO2 is estimated by XRD. The anatase phase forms at 500oC and phase transformation to the rutile phase occurs at 1200oC. Increase in the particle size is observed upon increasing the reaction temperature, and the phase ratio of the rutile phase is determined from a comparison with the calculated XRD data. Thus, we show that anatase and rutile TiO2 powders could be synthesized using AHFT as a raw material, and the obtained data are utilized for developing a new process for producing high-quality TiO2 powder.

Glass-ceramics were developed many years ago and have been applied in many fields such as electronics, chemistry, optics, etc. Much is already known about glass-ceramic technology, but many challenges in glass-ceramic research are still unresolved. Recently, large amounts of slag have steadily increased in the steel industry as by-products. To promote recycling of industrial waste, including steel industry slags, many studies have been performed on the fabrication of basalt-based highstrength glass-ceramics. In this study, we have fabricated such ceramics using various slags to replace high performance castbasalt, which is currently imported. Glass-ceramic material was prepared in similar chemical compositions with commercial cast-basalt through a pyro process using slags and power plant by-product (Fe-Ni slag, converter slag, dephosphorization slag, Fly ash). The properties of the glass-ceramic material were characterized using DTA, XRD, and FE-SEM; measurements of compressive strength, Vicker’s hardness, and abrasion were carefully performed. It is found that the prepared glass-ceramic material showed better performance than that of commercial cast-basalt.

A microfluidic reactor with computer-controlled programmable isocratic pumps and online detectors is employed as a combinatorial synthesis system to synthesize and analyze materials for fabricating CdSe quantum dots for various applications. Four reaction condition parameters, namely, the reaction temperature, reaction time, Cd/Se compositional ratio, and precursor concentration, are combined in synthesis condition sets, and the size of the synthesized CdSe quantum dots is determined for each condition. The average time corresponding to each reaction condition for obtaining the ultraviolet–visible absorbance and photoluminescence spectra is approximately 10 min. Using the data from the combinatorial synthesis system, the effects of the reaction conditions on the synthesized CdSe quantum dots are determined. Further, the data is used to determine the relationships between the reaction conditions and the CdSe particle size. This method should aid in determining and selecting the optimal conditions for synthesizing nanoparticles for diverse applications.

A Ni-based superalloy is widely used in many industrial field because of their high performance which is unusual class of metalic materials with an exceptional properties (high temperature strength, toughness, stress, oxidation/corrosion resistance). So, the most important application of Ni-superalloy is aircraft engines (gas turbine, turbine blade, etc), gas turbines for power generation and other challenging environments such as nuclear power and chemical plants. In the future, according to increasing the demand, amount of waste turbine blade is expected to be discarded. Therefore, it is necessary to research about recycling technology of waste Ni-based superalloy. In this study, we focused our research on the possibilities of recycling using waste Ni-based superalloy by AOD (argon-oxygen decarburization) process. Also, we were investigated experimental changes including Ar or O2 flow rate, reaction time, voltage to obtain the data of element component and structural changes. So, we evaluated the possibility about recovery of Ni or other metals.