scholarly journals Error Analysis of Clay-Rock Water Content Estimation with Broadband High-Frequency Electromagnetic Sensors—Air Gap Effect

Sensors ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 554 ◽  
Author(s):  
Thierry Bore ◽  
Norman Wagner ◽  
Sylvie Delepine Lesoille ◽  
Frederic Taillade ◽  
Gonzague Six ◽  
...  
Keyword(s):  
Error Analysis ◽  
Water Content ◽  
High Frequency ◽  
Air Gap ◽  
Gap Effect ◽  
Clay Rock ◽  
Electromagnetic Sensors

Study on Corrosion of X80 Pipeline Steel in Different Water Content of Soil

2014 ◽  
Vol 1015 ◽  
pp. 655-658
Author(s):  
Shu Zhen Yu ◽  
Guang Jun Xu ◽  
Han Hua Song ◽  
Xun Zhu ◽  
Wen We Lu ◽  
...  
Keyword(s):  
Water Content ◽  
High Frequency ◽  
Pipeline Steel ◽  
Electrochemical Corrosion ◽  
High Water ◽  
High Water Content ◽  
Linear Segment ◽  
X80 Pipeline Steel ◽  
The Third ◽  
In The Beginning

The electrochemical corrosion of X80 pipeline steel in Xinzhou’s soil with different water content is tested and analyzed. The corrosion signal time and frequency domain figure show that the corrosion signal fluctuates all the time in 30 days’ test with low water content (14%). The slope of high-frequency linear segment in the potential PSD is smaller than it is at the beginning. In the soil with the middle water content (18%), the intense wave motion lasts for 15 days. The noise fluctuation only exists before the third days when in the high water content soil (22%). After the third day, linear drift can be observed but no transient peak. The slope of high-frequency linear segment changes obviously compared with the situation in the beginning. And the high-frequency white noise appears.

scholarly journals Calculation improvement of no-load stray losses in induction motors with experimental validation

2015 ◽  
Vol 12 (3) ◽  
pp. 303-320
Author(s):  
Miloje Kostic
Keyword(s):  
High Frequency ◽  
Experimental Validation ◽  
Air Gap ◽  
New Classification ◽  
Iron Losses ◽  
Surface Iron ◽  
Space Harmonics ◽  
Rotor Cage

On the basis of the known fact that all air gap main flux density variations are enclosed by permeance slot harmonics, only one component of stray losses in rotor (stator) iron is considered in the new classification, instead of 2 components: rotor (stator) pulsation iron losses, and rotor (stator) surface iron losses. No-load rotor cage (high-frequency) stray losses are usually calculated. No-load stray losses are caused by the existence of space harmonics: the air-gap slot permeance harmonics and the harmonics produced by no-load MMF harmonics. The second result is the proof that the corresponding components of stray losses can be calculated separately for the mentioned kind of harmonics. Determination of the depth of flux penetration and calculations of high frequency iron losses are improved. On the basis of experimental validation, it is proved that the new classification of no-load stray losses and the proposed method for the calculation of the total value is sufficiently accurate.

scholarly journals Effect of Air Gap on Electrical Tree in Epoxy Resin Under High Frequency Bipolar Square-Wave Voltage

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5722
Author(s):  
Shihang Wang ◽  
Chuang Zhang ◽  
Hang Fu ◽  
Jiao Xiang ◽  
Jianying Li ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
High Frequency ◽  
Air Gap ◽  
Heat Accumulation ◽  
Air Gaps ◽  
Square Wave ◽  
Electrical Tree ◽  
Electrical Trees ◽  
Voltage Frequency ◽  
Tree Characteristics

Insulation fails quickly under high-frequency AC high voltage, especially bipolar square-wave voltage with a high dV/dt. It is of great significance to study the failure mechanism of epoxy casting insulation under such kind of voltage. In this paper, pin-plane epoxy casting insulation samples with air gaps were prepared, and the relation between the electrical trees under the high frequency bipolar square-wave voltage and the air gap conditions and voltage frequencies (1~20 kHz) were studied. Results indicated that, with the presence of air gaps, the electrical trees were bush-type and had a relatively slow growth rate, which was different from the fast-growing branch-type trees in the samples without air gap. The electrical tree characteristics related with the size of air gap and voltage frequency were also studied. The electrical tree grew faster under higher voltage frequency or with a smaller air gap. Results proved that discharge introduced a lot of defects for the surface layer of the epoxy resin samples and hence induced the possibility of multi-directional expansion of electrical trees. In addition, the resulting heat accumulation and unique charge transport synergistically affected the electrical tree characteristics under the high frequency bipolar square-wave voltage.

Water Content Estimation in Soils Using Novel Planar Electromagnetic Sensor Arrays

2013 ◽  
Vol 64 (5) ◽  
Author(s):  
Mohd Amri Md Yunus ◽  
Syahrul Hisyam Mohamad ◽  
Alif Syarafi M. Nor ◽  
Muhammad Hafis Izran ◽  
Sallehuddin Ibrahim
Keyword(s):  
Water Content ◽  
Sensor Array ◽  
Printed Circuit Board ◽  
Agricultural Soils ◽  
Sensor Arrays ◽  
Circuit Board ◽  
Waveform Generator ◽  
Electromagnetic Sensors ◽  
Electromagnetic Sensor ◽  
The Relationship

Agriculture is one of the important sectors for food supplies. Therefore, a tool for monitoring the agro-environment is important in order to maintain the permanence of agricultural soils. This paper suggests an alternative method for the detection of water content in soils by developing a sensor array with a combination of planar meander and interdigital electromagnetic sensors. The study involved sensor array fabrication using the printed circuit board (PCB) method. The experimental setup consisted of a frequency waveform generator and a signal oscilloscope to collect and analyse the sensors’ output, with VEE Agilent software used to establish the interface. A set of experiments was conducted to determine the relationship between the sensors’ output and the soils’ parameters. The performance of the system was observed where the sensors were tested with the addition of various kinds of soil samples with different concentrations of water content. The sensitivity of the developed sensors was evaluated where the best sensor was selected. Based on the outcomes of the experiments, the Y sensor array placement has the highest sensitivity and can be used to measure the water content in the soils where the data accuracy is compared

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