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An industrial fibreglass winding process is employed to apply graphene based sizing (0.2 wt% graphene concentration) on fibreglass surface. Both SEM and Raman spectroscopy characterization have proved that the coating of graphene on fibreglass surface is homogeneous and that the roughness of the fibreglass surface was improved. Long fiberglass-graphene reinforced PA66 pellets are successfully prepared through a pultrusion process. LGF-graphene-PA66 composites are produced following an injection molding process. Thermal conductivity was found to increase from 0.23 W/m · K−1 to 0.67 W/m · K−1 when compared with samples without graphene coating. The tensile strength of LGF-graphene-PA66 is 196 MPa while that of LGF-PA66 is 173 MPa. Tensile modulus is also found to increase to 13.5 GPa from 10.6 GPa after graphene coating. This new graphene coating process is a good method to produce high performance composites.

Ground subsidence induced by internal erosion around defective sewer pipes commonly occurs in urban areas of many cities over the world, which has caused substantial socioeconomic loss. Professional pipe design, inspection and maintenance demand a comprehensive understanding of the internal erosion mechanism due to defective pipes. This paper conducts a series of experimental, theoretical and numerical analyses aiming to propose a new method quantifying the erosion process around defective pipes. In this study, a laboratory experimental test of internal erosion was conducted using gap-graded soils, followed by the derivation of a nonlinear incremental governing equation for quantifying the erosion rate of soil on the basis of experimental results. After that, a new type of element was established to incorporate the proposed governing equation of erosion into Mohr-Coulomb constitutive soil model. Finally, this new element was adopted in a 2D soil-fluid coupled finite element analysis of soil erosion due to pipe defect. Results indicate that (1) the hydraulic head greatly affects cavity formation and soil loss, whereas the defect types have a little effect on eroded region, (2) visual images during test show that the soil erosion gradually slows down and eventually stabilizes along with the forming of soil skeleton, (3) the numerical results match well with the experimental results, demonstrating the effectiveness of both the theoretical method and numerical tool for the analysis of soil erosion around defective pipes.

The direct-billing collaboration between medical institutions and commercial health insurance institutions is an internationally applied method of commercial health insurance claims. This paper discusses the reasons why the direct-billing service of medical institutions is currently limited, including the trivial size of commercial health insurance and hospitals’ concern on cost control, by taking the practice of direct-billing service in a certain hospital in Wuhan as an example. It also summarizes the problems encountered in the operation, including the refusal to medical payment, the risks in excessive medical care, the increasing costs of medical institutions and acting against the equalization principle of medical service. The author then proposes several advices on the direct-billing service operated by hospitals, in terms of strengthening the risk control, taking part into the “Big Data” health management, reforming HIS system united with commercial insurance institutions and adjusting the pricing system of direct-billing service.

Many components can reach or exceed 109 cycles in their service time. When fatigue life is beyond 106, the Wöhler S-N curve was always considered to be asymptotic in horizontal axis, but the fatigue behaviour over 106 cycles can not be neglected. It is not usual to carry out a fatigue test beyond 109 cycles due to the conventional fatigue test’s constraints, time consuming and expensive. High strength steel is widely applied in automobile, railway industry after surface treatment in order to improve performance of material in practice. Carburizing process hardens surface to increase wear and fatigue resistance and shot peening has a beneficial effect on the material fatigue strength from the surface residual compressive stresses. A piezoelectric gigacycle fatigue machine is used to do the tests in gigacycle regime on specimens with different surface treatments. The effect of different surface treatments is investigated in gigacycle regime at a frequency of 20KHz with a fixed stress ratio R=0.1 at room temperature. Moreover, Scanning Electron Microscopy (SEM) observations of fracture surfaces are analyzed to evaluate the mechanism of damage related to surface treatments, microstructure scored inclusion size. The role of inclusions and microstructure is emphasized at 109 cycles.