Bleached Wood Supports for Floatable, Recyclable, and Efficient Three Dimensional Photocatalyst

To suppress the agglomeration of a photocatalyst, facilitate its recovery, and avoid photolysis of dyes, various support materials such as ceramic, carbon, and polymer have been investigated. However, these support materials pose the following additional challenges: ceramic supports will settle down at the bottom of their container due to their high density, while the carbon support will absorb the UV-vis light for its black color. Herein, we propose a floatable, UV transmitting, mesoporous bleached wood with most lignin removal to support P25 nanoparticles (BP-wood) that can effectively, recyclable, three dimensional (3D) photocatalytic degrade dyes such as methylene blue (MB) under ambient sunlight. The BP-wood has the following advantages: (1) The delignification makes the BP-wood more porous to not only quickly transport MB solutions upstream to the top surface, but is also decorated with P25 nanoparticles on the cell wall to form a 3D photocatalyst. (2) The delignification endows the BP-wood with good UV transmittance to undergo 3D photocatalytic degradation under sunlight. (3) It can float on the surface of the MB solution to capture more sunlight to enhance the photodegradation efficiency by suppressing the photolysis of MB. (4) It has comparable or even better photocatalytic degradation of 40 mg/L and 60 mg/L MB than that of P25 nanoparticles suspension. (5) It is green, recyclable, and scalable

Efficient service discovery in mobile social networks for smart cities

Mobile social networks (MSNs) play an important role in the process of the development of smart cities. Citizens can interact and engage with services provided by MSNs. Smart city services enhance their quality of life. With the popularity of smart phones, mobile social activities have become an important component of citizens’ daily life. People can post their social contents to their remote friends and can access shared information in the cycles of friends anytime and anywhere through their mobile devices. This human-centered social approach generates enormous amounts of social data that are distributed across various smart devices. Efficient service discovery from such cycles of friends is a fundamental challenge for MSNs. This paper proposes a friends’ cycle service discovery (FCSD) model for searching social services in MSNs based on human sociological theories and social strategies. In the proposed FCSD network, intelligent network nodes with common social interests can self-organize to interact and form social cycles with other potential nodes, and further can co-operate autonomously to identify and discover useful services from cycles of friends and cycles of friends’ friends. The proposed model has been simulated and evaluated in a decentralized mobile social environment with an evolving network. The experimental results show that the FCSD model exhibits better performance compared with relevant state-of-the-art services search methods

Promotion Effect of Carbon Nanotubes-Doped SDS on Methane Hydrate Formation

To achieve greater performance of a low concentration of sodium dodecyl sulfate (SDS) in methane hydrate formation, SDS solutions were doped with pristine carbon nanotubes (pCNTs) and the oxidized forms (OCNTs). With nanotubes as the predominant accelerant in the mixed promoters, the nucleation stage could be shorten efficiently due to the continuous Brownian motion of more nanoparticles. The mixed promoters exerted more pronounced influence on the methane hydrate growth rate compared to the pure SDS, with the OCNTs-SDS system performing slightly better owing to the high dispersion and stability of the OCNTs in the aqueous SDS solutions. Nevertheless, the promotion effects of highly concentrated pCNTs or OCNTs could be weakened possibly due to the aggregation of nanotubes