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Cenospheres, as an important value-added product in fly ash, are particles with a hollow spherical structure. Cenospheres are widely used in industry for their unique properties. However, most of the industries use wet separation, which consumes a lot of water and land resources and pollutes the ecological environment, so it is of great significance to study dry separation. In this study, a customized cyclone separator was used to separate cenospheres from fly ash, and the effect of inlet wind speed on the separation efficiency was investigated. The best separation efficiency was achieved at an inlet wind speed of 13 m/s for a fly ash mixture configured with 15% hollow cenospheres, with a Newton's efficiency of 0.687, which is slightly higher than that of the wet method of 0.6. The larger the pore size, the easier the cenospheres could be separated.

Hollow microbeads, derived from fly ash emitted by power plants, are hollow microbeads composed of various compounds including SiO2 and Al2O3. These microspheres exhibit a high specific surface area and stable chemical properties. In this work, HM-MoS2 was synthesized through a two-step hydrothermal method to address the issues of low adsorption efficiency and high operational costs associated with the utilization of hollow microbeads in actual power plant applications. The experiments demonstrated that under simulated power plant flue gas conditions, the adsorption efficiency of HM-15 for elemental mercury (Hg0) exceeded 96%. Additionally, HM-15 displayed resistance to SO2 and NO gases, indicating its potential as a mercury adsorbent material with promising industrial applications.

In the past decades, microfluidic chips have been one of the hottest research topics in the "lab-on-a-chip" field. However, it is still a challenge for design the perfect microchannels with high functional integration, complex geometry, and high production efficiency. This review paper provides a comprehensive overview of microfluidic structural models and designs, manufacturing techniques, and bonding methods. The effect of three types of microfluidic channel structure models and their configuration parameters on the fluid behaviors of microfluidics was investigated. Surface-to-volume ratio of the flow channel is a critical parameter for determining the mixing and diffusion capabilities of the microfluidic devices (MDs). Thereafter, the main manufacturing techniques for microstructures were discussed, including etching, photolithography, soft lithography, molding, mechanical micro-machining, laser beam micromachining, printing, and 3D printing. We performed a statistical analysis to discuss the relative advantages and disadvantages of these manufacturing methods. In addition, the current bonding methods for MDs were also summarized, including thermal bonding, solution adhesive bonding, dry adhesive bonding, plasma bonding, and anodic bonding. a comparison of different bonding methods was presented to provide a reference to select a suitable bonding method for the assembly of microfluidic device. Finally, the tendencies and challenges of microchannel manufacturing were discussed, and the prospects were also provided. [ABSTRACT FROM AUTHOR]

The separation of cenospheres is an important method for fly ash recycling, and there is no efficient and less polluting method available for separating cenospheres. This paper proposes the dry separation of cenospheres using a cyclone separator, which utilizes the small density of cenospheres as a feature to separate them. The corresponding numerical simulations of the cyclone separator model used to separate the cenospheres were carried out by a CFD analysis, after which the size of the radius of the upper discharge opening and the height of the sloping wall of the cyclone separator were analyzed by simulation; the effect of the incident velocity on the Newton's efficiency of the separation of the cenospheres was also analyzed. The simulation results indicate that the Newton's efficiency can reach 0.55 when the radius of the upper feed port is 90 mm, the height of the inclined wall is 400 mm, and the incident speed is 2.5 m/s. [ABSTRACT FROM AUTHOR]

Pitch system is an essential subsystem of a wind turbine, which is to efficiently capture and maximize the utilization of wind energy by controlling the rotation of the blades. Its safety and stability directly affect the operation of wind farm, but the complex internal mechanics and control system makes pitch system very susceptible to failure. This paper first summarized fault diagnosis and fault prediction about pitch system of wind turbine. We were briefly introduced the main faults of electric-driven and hydraulic-driven pitch systems, the sources of diagnostic data, and the methods pre-processing. Then, four types of fault diagnosis methods and three fault prediction methods were discussed to provide a valuable guidance for the maintenance of pitch systems. Finally, the prospect on the future development of fault diagnosis and fault prediction techniques about pitch system was suggested to further improve the safety of wind turbines. [ABSTRACT FROM AUTHOR]

The MgO‐MoO3 system shows significant potential for applications in microwave dielectric ceramics. However, the formation mechanism, crystal structures, and microwave dielectric properties of this system have not been systematically investigated. This work aims to comprehensively study the crystal structures, phase transitions, and microwave dielectric properties of compounds in the MgO‐MoO3 system. In particular, the research delves into the unexplored transformation mechanism from β‐MgMo2O7 to α‐MgMo2O7 and MgMoO4. As a result, the three compounds exhibiting favorable microwave dielectric properties have been successfully fabricated. These compounds can be effectively sintered at temperatures ranging from 685 to 900°C and exhibited dielectric constants (εr) ranging from 5.41 to 6.89, as well as Qf values ranging from 100 000 to 130 000 GHz. Additionally, prototype microstrip antennas are designed and fabricated using β‐MgMo2O7 and MgMoO4 ceramics as substrates. The obtained antenna's performance is excellent, with S11 values below −30 dB and a gain exceeding 6 dB at 5.8 GHz, highlighting the potential of the developed ceramics for practical applications in microwave devices. [ABSTRACT FROM AUTHOR]