Although oxide nanoparticles are ubiquitous in science and technology, a multitude of compositions, phases, structures, and doping levels exist, each one requiring a variety of conditions for their synthesis and modification. Besides, experimental procedures are frequently dominated by high temperatures or pressures and by chemical contaminants or waste. In recent years, laser synthesis of colloids emerged as a versatile approach to access a library of clean oxide nanoparticles relying on only four main strategies running at room temperature and ambient pressure: laser ablation in liquid, laser fragmentation in liquid, laser melting in liquid and laser defect-engineering in liquid. Here, established laser-based methodologies are reviewed through the presentation of a panorama of oxide nanoparticles which include pure oxidic phases, as well as unconventional structures like defective or doped oxides, non-equilibrium compounds, metal-oxide core-shells and other anisotropic morphologies. So far, these materials showed several useful properties that are discussed with special emphasis on catalytic, biomedical and optical application. Yet, given the endless number of mixed compounds accessible by the laser-assisted methodologies, there is still a lot of room to expand the library of nano-crystals and to refine the control over products as well as to improve the understanding of the whole process of nanoparticle formation. To that end, this review aims to identify the perspectives and unique opportunities of laser-based synthesis and processing of colloids for future studies of oxide nanomaterial-oriented sciences.

https://chemistry-europe.onlinelibrary.wiley.com/doi/pdf/10.1002/chem.202000686

Room-Temperature Laser Synthesis in Liquid of Oxide, Metal-Oxide Core-Shells, and Doped Oxide Nanoparticles

Energy management is an enabling technique to guarantee the reliability and economy of hybrid electric systems. This paper proposes a novel machine learning-based energy management strategy for a hybrid electric bus (HEB), with an emphasized consciousness of both thermal safety and degradation of the onboard lithium-ion battery (LIB) system. Firstly, the deep deterministic policy gradient (DDPG) algorithm is combined with an expert-assistance system, for the first time, to enhance the “cold start” performance and optimize the power allocation of HEB. Secondly, in the framework of the proposed algorithm, the penalties to over-temperature and LIB degradation are embedded to improve the management quality in terms of the thermal safety enforcement and overall driving cost reduction. The proposed strategy is tested under different road missions to validate its superiority over state-of-the-art techniques in terms of training efficiency and optimization performance.

Battery-Involved Energy Management for Hybrid Electric Bus Based on Expert-Assistance Deep Deterministic Policy Gradient Algorithm

An analytical calculation method of the load distribution and stiffness of an angular contact ball bearing

Path-tracking of autonomous vehicles using a novel adaptive robust exponential-like-sliding-mode fuzzy type-2 neural network controller

Multi-objective optimization design and control of plug-in hybrid electric vehicle powertrain for minimization of energy consumption, exhaust emissions and battery degradation

Adaptive fuzzy iterative control strategy for the wet-clutch filling of automatic transmission

Optimized control of engine start assisted by the disconnect clutch in a P2 hybrid automatic transmission

Design and analysis of a novel multi-speed automatic transmission with four degrees-of-freedom

A model to predict initiation and propagation of micro-pitting on tooth flanks of spur gears

The evaluation of wear progress of gear tooth flanks made of 16MnCr5 was performed using non-destructive micro-magnetic testing, specifically Barkhausen noise (BN) and incremental permeability (IP). Based on the physical interaction of the microstructure with the magnetic field, the micro-magnetic characterization allowed the analysis of changes of microstructure caused by wear, including phase transformation and development of residual stresses. Due to wide parameter variation and application of bandpass filter frequencies of micro-magnetic signals, it was possible to indicate and separate the main damage mechanisms considering the wear development. It could be shown that the maximum amplitude of BN correlates directly with the profile form deviation and increases with the progress of wear. Surface investigations via optical and scanning electron microscopy indicated strong surface fatigue wear with micro-pitting and micro-cracks, evident in cross-section after 3 × 10⁵ cycles. The result of fatigue on the surface layer was the decrease of residual compression stresses, which was indicated by means of coercivity by BN-analysis. The different topographies of the surfaces, characterized via confocal white light microscopy, were also reflected in maximum BN-amplitude. Using complementary microscopic characterization in the cross-section, a strong correlation between micro-magnetic parameters and microstructure was confirmed and wear progress was characterized in dependence of depth under the wear surface. The phase transformation of retained austenite into martensite according to wear development, measured by means of X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) was also detected by micro-magnetic testing by IP-analysis.

/pdf/micro-magnetic-and-microstructural-characterization-of-wear-4bblh1g8es.pdf

Peter Tenberge

Papers

Adaptive fuzzy iterative control strategy for the wet-clutch filling of automatic transmission

Optimized control of engine start assisted by the disconnect clutch in a P2 hybrid automatic transmission

Design and analysis of a novel multi-speed automatic transmission with four degrees-of-freedom

A model to predict initiation and propagation of micro-pitting on tooth flanks of spur gears

Micro-Magnetic and Microstructural Characterization of Wear Progress on Case-Hardened 16MnCr5 Gear Wheels.