Measurements of gamma radiation （200 keV to 10 MeV） were performed between May 25 to September 30 2016 at ITA （Technological Institute of Aeronautics） in Sao Jose dos Campos, SP, Brazil. Detector and associated el...Measurements of gamma radiation （200 keV to 10 MeV） were performed between May 25 to September 30 2016 at ITA （Technological Institute of Aeronautics） in Sao Jose dos Campos, SP, Brazil. Detector and associated electronics were previously calibrated in the laboratory of ITA using radioactive sources Cs-137, Po-210 and Sr-90. These sources provide gamma-ray energies in 0.662 keV alpha particles of 5.4 MeV and 0.90 keV electrons, respectively. Detector is a scintillator Sodium Iodide activated with Thallium [NaI（Tl）] associated to a photomultiplier and electronic devices which gather, store, distribute and structure data so users can analyze them. During the period of May-September, the experimental set was installed in an open room on a tower 25 meters above the ground. Measurements indicated variations of ionizing radiation in function of dry weather, rain, cold fronts passes and presence of fog in the area; the sample time interval was minute by minute. This study discusses the analysis and the dynamics of how to measure meteorological parameters using an ionizing radiation system.展开更多
Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the u...Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the user are interested in the results of PD measurements. However, PDs hardly represent the cause of the failure, more likely they are claimed as the outcome of a failure. This paper deals with the insulation of a 6 kV electrical machine, whereas PD measurements were carried out at a single stator from wound coils. During manufacturing, these coils were equipped with different materials for the OCP （outer corona protection）. Using different PD measurement systems and different bandwidths, investigations of the PD behavior of the coils were carried out. Additionally, the surface resistivity of the corona protection was determined. As a result, conclusions for the correlations between the resistance of the OCP as well as the PD behavior are stated. Furthermore, the influence of using different measurement systems, different measuring circuits, and different bandwidths is shown.展开更多
In order to explore the mineral resources buried in sea mud,it is necessary to use seabed resistivity measuring equipment,which works closer to the sediments than ordinary ship-based geophysical measuring equipment. B...In order to explore the mineral resources buried in sea mud,it is necessary to use seabed resistivity measuring equipment,which works closer to the sediments than ordinary ship-based geophysical measuring equipment. Because of the harsh environment of seafloor,high pressure and highly conductive seawater,marine magnetotelluric method developed slowly. The sea floor environment is similar to the environment of logging, According to the design of dual lateral logging equipment,a new equipment for seafloor electrical resistivity measurement is designed. Four 3D FEM models that contain resistivity abnormal targets are built to test the ability of this equipment to locate different shape of shallow buried resistivity abnormal targets in sea mud. The authors propose the method to correct the response curve while the bottom surface of this equipment is suspended or not parallel to the seafloor. The resistivity of targets can be calculated accurately.展开更多
In recent years, triboelectric nanogenerators have attracted much attention because of their unique potential in self-powered nanosensors and nanosystems. In this paper, we report a cylindrical spiral tdboelectric nan...In recent years, triboelectric nanogenerators have attracted much attention because of their unique potential in self-powered nanosensors and nanosystems. In this paper, we report a cylindrical spiral tdboelectric nanogenerator （S-TENG）, which not only can produce high electric output to power display devices, but also can be used as a self-powered displacement sensor integrated on a measurement ruler. At a sliding speed of 2.5 m/s, S-TENG can generate a short-circuit current （Isc） of 30 μA and an open-circuit voltage （Voc） of 40 V. As the power source, we fabricate a transparent and flexible hand-driven S-TENG. Furthermore, we demonstrate a self-powered S-TENG-based measuring tapeline that can accurately measure and display the pulled-out distance without the need for an extra battery. The results obtained indicate that TENG-based devices have good potential for application in self-powered measurement systems.展开更多
文摘Measurements of gamma radiation （200 keV to 10 MeV） were performed between May 25 to September 30 2016 at ITA （Technological Institute of Aeronautics） in Sao Jose dos Campos, SP, Brazil. Detector and associated electronics were previously calibrated in the laboratory of ITA using radioactive sources Cs-137, Po-210 and Sr-90. These sources provide gamma-ray energies in 0.662 keV alpha particles of 5.4 MeV and 0.90 keV electrons, respectively. Detector is a scintillator Sodium Iodide activated with Thallium [NaI（Tl）] associated to a photomultiplier and electronic devices which gather, store, distribute and structure data so users can analyze them. During the period of May-September, the experimental set was installed in an open room on a tower 25 meters above the ground. Measurements indicated variations of ionizing radiation in function of dry weather, rain, cold fronts passes and presence of fog in the area; the sample time interval was minute by minute. This study discusses the analysis and the dynamics of how to measure meteorological parameters using an ionizing radiation system.
文摘Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the user are interested in the results of PD measurements. However, PDs hardly represent the cause of the failure, more likely they are claimed as the outcome of a failure. This paper deals with the insulation of a 6 kV electrical machine, whereas PD measurements were carried out at a single stator from wound coils. During manufacturing, these coils were equipped with different materials for the OCP （outer corona protection）. Using different PD measurement systems and different bandwidths, investigations of the PD behavior of the coils were carried out. Additionally, the surface resistivity of the corona protection was determined. As a result, conclusions for the correlations between the resistance of the OCP as well as the PD behavior are stated. Furthermore, the influence of using different measurement systems, different measuring circuits, and different bandwidths is shown.
文摘In order to explore the mineral resources buried in sea mud,it is necessary to use seabed resistivity measuring equipment,which works closer to the sediments than ordinary ship-based geophysical measuring equipment. Because of the harsh environment of seafloor,high pressure and highly conductive seawater,marine magnetotelluric method developed slowly. The sea floor environment is similar to the environment of logging, According to the design of dual lateral logging equipment,a new equipment for seafloor electrical resistivity measurement is designed. Four 3D FEM models that contain resistivity abnormal targets are built to test the ability of this equipment to locate different shape of shallow buried resistivity abnormal targets in sea mud. The authors propose the method to correct the response curve while the bottom surface of this equipment is suspended or not parallel to the seafloor. The resistivity of targets can be calculated accurately.
基金Acknowledgements Thanks for the support from the ＂thousands talents＂ program for pioneer researcher and his innovation team, China, National Natural Science Foundation of China （Nos. 51432005 and 61405131）, Beijing Natural Science Foundation （No. 4154090）, Beijing City Committee of science and technology （Nos. Z131100006013004 and Z131100006013005）.
文摘In recent years, triboelectric nanogenerators have attracted much attention because of their unique potential in self-powered nanosensors and nanosystems. In this paper, we report a cylindrical spiral tdboelectric nanogenerator （S-TENG）, which not only can produce high electric output to power display devices, but also can be used as a self-powered displacement sensor integrated on a measurement ruler. At a sliding speed of 2.5 m/s, S-TENG can generate a short-circuit current （Isc） of 30 μA and an open-circuit voltage （Voc） of 40 V. As the power source, we fabricate a transparent and flexible hand-driven S-TENG. Furthermore, we demonstrate a self-powered S-TENG-based measuring tapeline that can accurately measure and display the pulled-out distance without the need for an extra battery. The results obtained indicate that TENG-based devices have good potential for application in self-powered measurement systems.
