A new Fe-Cr-Mo-B-C amorphous alloy is designed, which offers high mechanical strength, corrosion resistance as well as high glass-forming ability and its gas-atomized amorphous powder is deposited on an ASTM A213-T91 steel substrate using the high-velocity oxygen fuel (HVOF) process. The hybrid coating layer, consisting of nanocrystalline and amorphous phases, exhibits strong bonding features with the substrate, without revealing significant pore formation. By the coating process, it is possible to obtain a dense structure in which pores are hardly observed not only inside the coating layer but also at the interface between the coating layer and the substrate. The coating layer exhibits good adhesive strength as well as good wear resistance, making it suitable for coating layers for biomass applications.
Iron-based amorphous powder attracts increasing attention because of its excellent soft magnetic properties and low iron loss at high frequencies. The development of an insulating layer on the surface of the amorphous soft magnetic powder is important for minimizing the eddy current loss and enhancing the energy efficiency of highfrequency devices by further increasing the electrical resistivity of the cores. In this study, a hybrid insulating coating layer is investigated to compensate for the limitations of monolithic organic or inorganic coating layers. Fe2O3 nanoparticles are added to the flexible silicon-based epoxy layer to prevent magnetic dilution; in addition TiO2 nanoparticles are added to enhance the mechanical durability of the coating layer. In the hybrid coating layer with optimal composition, the decrease in magnetic permeability and saturation magnetization is suppressed.
Phosphorus is one of the limiting nutrients for the growth of phytoplankton and algae and is therefore one of leading causes of eutrophication. Most phosphorous in water is present in the form of phosphates. Different technologies have been applied for phosphate removal from wastewater, such as physical, chemical precipitation by using ferric, calcium or aluminum salts, biological, and adsorption. Adsorption is one of efficient method to remove phosphates in wastewater. To find the optimal media for phosphate removal, physical characteristics of media was analysed, and the phosphate removal efficiency of media (silica sand, slag, zeolite, activated carbon) was also investigated in this study. Silica sand showed highest relative density and wear rate, and phosphate removal efficiency. Silica sand removed about 36% of phosphate. To improve the phosphate removal efficiency of silica sand, Fe coating was conducted. Fe coated silica sand showed 3 times higher removal efficiency than non-coated one.
생체 내 필수 영양소이자 영양 보충제 성분인 아연과 철은 수용액 상에서 분산 안정성이 낮으며, 철의 경우 주변 환경의 영향으로 쉽게 산화되는 특성을 가지고 있다. 최근에는 이러한 문제점을 보완하기 위해 나노 기술을 이용한 식품 개발이 이루어지고 있는데, 본 연구에서 사용 된 소재인 SunActive Zn 및 SunActive Fe는 나노 크기의 식품용 아연과 철을 친수성 폴리머로 코팅함으로써 분산 안정성, 수용액상 용해도 및 관능 특성을 향상시켰으나 그에 따른 독성 및 흡수율에 대한 연구는 미비한 실정이다. 따라서 본 연구에서는 랫드에 28일 반복 경구투여에 의한 독성시험 을 수행하였으며, 약동학적 연구를 통해 흡수율을 규명하고자 하였다. 비교 연구를 위해 대조 물질로 산화아연(ZnO, 100 nm) 나노물질 및 ferric pyrophosphate를 각각 사용하였다. 그 결과 SunActive Zn 및 SunActive Fe는 반복투여에 의한 유의적 독성 현상을 보이지 않았으며, 폴리머 코팅에 의해 아연 및 철의 체내 흡수율이 향상될 수 있는 것으로 나타났다. 이와 같은 연구 결과는 기능성 성분 및 체내 필수 영양분의 흡수율을 향상시키기 위한 새로운 개발 전략 을 제시한다.