To clarify and control the collapse and weighting of main roof in longwall mining is one of the important research problems in ground control. Based on the results of physical model experiment and field measurement, t...To clarify and control the collapse and weighting of main roof in longwall mining is one of the important research problems in ground control. Based on the results of physical model experiment and field measurement, the behaviour of main roof above trapezoidal goaf or with fault is studied in this paper. The fracture and weighting of main roof above trapezoidal goaf are different from those above rectangular goaf. It depends on the mechanical relation between main roof blocks whether the plate blocks of main roof on both sides of fault simultaneously break and collapse.展开更多
This work highlights the design and the realization of an automatic solar-panel orientation system in order to achieve high-performances. The solar panel sensor constitutes the main part of the system, since it ensure...This work highlights the design and the realization of an automatic solar-panel orientation system in order to achieve high-performances. The solar panel sensor constitutes the main part of the system, since it ensures the pursuit of the sunbeam. The management of the system, depending on the movements, the presence of sun, and the regular checkup of the system evolution, is ensured by an electronic unit executed around a microcontroller.展开更多
文摘To clarify and control the collapse and weighting of main roof in longwall mining is one of the important research problems in ground control. Based on the results of physical model experiment and field measurement, the behaviour of main roof above trapezoidal goaf or with fault is studied in this paper. The fracture and weighting of main roof above trapezoidal goaf are different from those above rectangular goaf. It depends on the mechanical relation between main roof blocks whether the plate blocks of main roof on both sides of fault simultaneously break and collapse.
文摘This work highlights the design and the realization of an automatic solar-panel orientation system in order to achieve high-performances. The solar panel sensor constitutes the main part of the system, since it ensures the pursuit of the sunbeam. The management of the system, depending on the movements, the presence of sun, and the regular checkup of the system evolution, is ensured by an electronic unit executed around a microcontroller.
