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•A Q-learning approach has been done to optimize energy management hybrid vehicles.•Reward function has been included fuel consumption and battery life cycle.•Cycle knowledge and exact vehicle model are not required in the Q-learning method.•The applied method is provided for various driving cycles.•The proposed method reduces fuel consumption and maximizes battery life.

We present an h-adaptive version of the spacetime-discontinuous Galerkin (SDG) finite element method for linearized elastodynamics (Abedi et al., 2006). The adaptive version inherits key properties of the basic SDG formulation, including element-wise balance of linear and angular momentum, complexity that is linear in the number of elements and oscillationfree shock capturing. Unstructured spacetime grids allow simultaneous adaptation in space and time. A localized patch-by-patch solution process limits the cost of reanalysis when the error indicator calls for more refinement. Numerical examples demonstrate the method’s performance and shock-capturing capabilities.

Statistical volume elements (SVEs) are used to homogenize fracture strength of rock, based on the microcrack statistics of a real-world Yuen-Long marble sample. The small size of SVEs enables maintaining inhomogeneities in fracture properties with lower computational cost compared to methods that explicitly model microcracks at macroscale. Maintaining inhomogeneity is important to capture realistic fracture patterns in rock as a quasi-brittle material. Uniaxial tensile, uniaxial compressive, and shear strengths are derived for arbitrary angle for loading and orientation of a single crack by using the linear elastic fracture mechanics (LEFM) method and incorporating frictional effects. Mesoscopic fracture strength fields are generated for different strengths and angle of loading by traversing the spatial domain with circular SVEs. Increasing the SVE size smoothens the spatial inhomogeneity and angular anisotropy of homogenized strengths. Spatial and angular covariance functions of the random fields are obtained to demonstrate how fracture strength varies in space and by changing the angle of loading. Two isotropic and anisotropic rock domains are studied and shown to have very different single- and two-point statistics. Macroscopic fracture simulations by an asynchronous spacetime discontinuous Galerkin (aSDG) method demonstrate that most macroscopic cracks for the anisotropic domain are aligned with the weakest strength planes.

This paper aims to consider the potential of Eruca sativa(ES) crops, which is a plant with a short production cycle and drought tolerance, for biodiesel feedstock source and to compare exhaust emissions and engine performance of using its biodiesel blends with pure diesel. Thus, ES methyl ester was produced through a transesterification reaction by using KOH as a catalyst. The fatty acid composition of ES biodiesel was determined by FTIR and GC–MS analysis and its properties were compared with ASTM biodiesel standard and regular diesel. The GC–MS analysis showed that oleic and palmitic acids were the main compounds in ES methyl ester. Then, biodiesel blends were injected into a single-cylinder 4-stroke diesel engine at various speeds. Experimental tests revealed that using ES methyl ester led to reductions in HC and CO emissions substantially and NOx emissions moderately, whereas there was a minor rise in CO2emissions. Moreover, a slight decrease in engine power and an increase in specific fuel consumption (5.3%) occurred, which are acceptable due to the reduction of exhaust emissions. Based on the results, ES biodiesel has the capability to apply in CI engines and to diminish emissions.

To accurately simulate fracture, it is necessary to account for small-scale randomness in the properties of a material. Apparent properties of statistical volume element (SVE) can be characterized below the scale of a representative volume element (RVE). Apparent properties cannot be defined uniquely for an SVE, in the manner that unique effective properties can be defined for an RVE. Both constitutive behavior and material strength properties in SVE must be statistically characterized. The geometrical partitioning method can be critically important in affecting the probability distributions of mesoscale material property parameters. Here, a Voronoi tessellation-based partitioning scheme is applied to generate SVE. Resulting material property distributions are compared with those from SVE generated by square partitioning. The proportional limit stress of the SVE is used to approximate SVE strength. Superposition of elastic results is used to obtain failure strength distributions from boundary conditions at variable angles of loading.