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In this study, a simple two-step process was developed to render zinc (Zn) surfaces super-hydrophobic for the purpose of lowering friction and increasing wear resistance. Zn substrates were immersed in an aqueous solution of N,N-dimethylformamide (4%, volume fraction v/v) to fabricate a ZnO film consisting of uniform and wellpacked nanorods. A self-assembled monolayer of stearic acid was then prepared on the ZnO-nanorod film to acquire super-hydrophobicity. Scanning electron microscopy, Fourier transform infrared microscopy, and water contactangle measurements were employed to analyze the morphological features, the chemical composition, and superhydrophobicity of freshly prepared samples. Moreover, the friction and wear behavior of the organic-inorganic composite film sliding against steel was evaluated in a ball-onplate configuration using a UMT-3 friction and wear tester. It was found that the stearic acid overcoat on the nanostructured ZnO film led to a large water contact angle of *155°as well as to significantly decreased friction and greatly extended wear resistance.

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In this paper, we consider the constrained energy minimizing generalized multiscale finite element method (CEM-GMsFEM) with discontinuous Galerkin (DG) coupling for the linear elasticity equations in highly heterogeneous and high contrast media. We will introduce the construction of a DG version of the CEM-GMsFEM, such as auxiliary basis functions and offline basis functions. The DG version of the method offers some advantages such as flexibility in coarse grid construction and sparsity of resulting discrete systems. Moreover, to our best knowledge, this is the first time where the proof of the convergence of the CEM-GMsFEM in the DG form is given. Some numerical examples will be presented to illustrate the performance of the method.