Petrochemical storage tanks are generally inspected when the tank is offline mostly to assess the extent of underside corrosion on the tank floor. Emptying, cleaning and opening a tank for inspection take many months ...Petrochemical storage tanks are generally inspected when the tank is offline mostly to assess the extent of underside corrosion on the tank floor. Emptying, cleaning and opening a tank for inspection take many months and are very expensive. Inspection costs can be reduced significantly by inserting robots through manholes on the tank roof to pertbrm non-destructive testing （NDT）. The challenge is to develop robots that can operate safely in explosive and hazardous environments and measure the thickness of floor plates using ultrasound sensors. This paper reports on the development of a small and inexpensive prototype robot （NDTBOT） which is designed to be intrinsically safe for zone zero operation. The robot ＂hops＂ across the floor to make measurements, without any external moving parts. The paper describes the design, experimental testing of the NDTBOT and presents results of steel plate thickness measurements made under water.展开更多
At the beginning of the 21th century, the integration of teacher education has become a hot issue in the studies of China＇ s teacher education. In this paper, a discussion is conducted from the change from normal edu...At the beginning of the 21th century, the integration of teacher education has become a hot issue in the studies of China＇ s teacher education. In this paper, a discussion is conducted from the change from normal education to teacher education, the intension of teacher education integration, and the exploration on China＇ s teacher education integration, and then the existing problems are analyzed, and finally the future research direction is raised.展开更多
文摘Petrochemical storage tanks are generally inspected when the tank is offline mostly to assess the extent of underside corrosion on the tank floor. Emptying, cleaning and opening a tank for inspection take many months and are very expensive. Inspection costs can be reduced significantly by inserting robots through manholes on the tank roof to pertbrm non-destructive testing （NDT）. The challenge is to develop robots that can operate safely in explosive and hazardous environments and measure the thickness of floor plates using ultrasound sensors. This paper reports on the development of a small and inexpensive prototype robot （NDTBOT） which is designed to be intrinsically safe for zone zero operation. The robot ＂hops＂ across the floor to make measurements, without any external moving parts. The paper describes the design, experimental testing of the NDTBOT and presents results of steel plate thickness measurements made under water.
文摘At the beginning of the 21th century, the integration of teacher education has become a hot issue in the studies of China＇ s teacher education. In this paper, a discussion is conducted from the change from normal education to teacher education, the intension of teacher education integration, and the exploration on China＇ s teacher education integration, and then the existing problems are analyzed, and finally the future research direction is raised.
