A disc-on-disc type tester was used to examine the role of fullerene nanoparticles dispersed in a mineral oil-based lubricant. In the friction test, the friction coefficient of the disc specimen immersed in the nano-oil was significantly lower than that of the disc specimen immersed in the mineral oil. This suggests that the nanoparticles dispersed in mineral oil played the important role in the lubrication enhancement of nano-oil. A series of experiments in this study were carried out to delineate the two effects [i.e., direct effect (e.g., rolling/sliding/filming) and surface enhancement effect (e.g., mending/polishing)] of nanoparticles for nano-oil-based lubrication enhancement. The disc specimens immersed in the nano-oils during the friction test was removed, and then they were re-immersed in new mineral oil for an additional friction test. The direct and surface enhancement effect of nanoparticles was then visualised by the evolution of the friction coefficient of the disc specimen immersed in the mineral-and nano-oil. The results showed that the direct effect of nanoparticles was much more dependent on the magnitude of the applied normal load than the surface enhancement effect.

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In a departure from the past, unmanned underwater vehicles (UUVs) and unmanned surface vehicles (USVs) are increasingly needed for complementary cooperation in military, scientific, and commercial applications, because this is more efficient than standalone operations. Information sharing through acoustic underwater communication is vital for complementary cooperation between USVs and UUVs. Normally, since USVs have advantages in terms of wide operational boundaries compared to UUVs, they are efficient for tracking UUVs. In this paper, we suggest a UUV tracking algorithm for a USV. The tracking algorithm’s development consists of three main software models: an estimation based on an extended Kalman filter (EKF) with a navigation smoothing method, guidance based on multimode guidance, and re-searching based on a pattern. In addition, the algorithm provides a procedure for tracking UUVs in complex acoustic underwater communication environments. The tracking algorithm was tested in a simulated environment to check the performance of each method, and implemented with a USV system to verify its validity and stability in sea trials. The UUV tracking algorithm of the USV shows stable and efficient performance.

The design of an energy management strategy is critical to improving the fuel efficiency of a vehicle system with an alternative powertrain system, such as hybrid electric vehicles or fuel cell electric vehicles. In particular, in fuel cell electric vehicles, the energy management strategy should consider system degradation and fuel savings because the hardware cost of the fuel cell system is much higher than that of a conventional powertrain system. In this paper, an easily implantable near-optimal energy management controller is proposed. The proposed controller distributes power generation between the fuel cell and the battery to simultaneously minimize system degradation and fuel usage. The controller is designed to consider the degradation cost and fuel cost in the framework of the equivalent consumption minimization strategy concept. The proposed controller was validated with a fuel cell electric vehicle model in MATLAB/Simulink (MathWorks, Natick, USA). The proposed control strategy showed significant overall cost reduction compared to a thermostat control strategy and a conventional Equivalent Consumption Minimization Strategy (ECMS) strategy.