Monitoring of Dry Bands and Discharge Activities at the Surface of Textured Insulators with AC Clean Fog Test Conditions

The aim of this study is the presentation of the results of an in-lab comparative study of electrical and thermal monitoring of artificially polluted, HTV-textured silicone rubber insulators, with different pollution levels. This work is a preliminary study of an in-situ monitoring of 400 kV SiR textured in a polluted environment. The results showed that the rms leakage current magnitude and pulses, and the average dissipated power depended on the pollution levels and the dry-bands formation. The discharge activity and their nature are governed by the pollution level and the voltage. A differentiation and a quantification between dry-band discharge onset and dry-band arc inception is highlighted.

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Microwave Sensors for In Situ Monitoring of Trace Metals in Polluted Water

Sensors ◽

10.3390/s21093147 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3147

Author(s):

Ilaria Frau ◽

Stephen Wylie ◽

Patrick Byrne ◽

Patrizia Onnis ◽

Jeff Cullen ◽

...

Keyword(s):

Trace Metals ◽

In Situ Monitoring ◽

Polluted Water ◽

Pollution Level ◽

Mining Areas ◽

Low Concentrations ◽

The Uk ◽

Microwave Sensors ◽

Immediate Response

Thousands of pollutants are threatening our water supply, putting at risk human and environmental health. Between them, trace metals are of significant concern, due to their high toxicity at low concentrations. Abandoned mining areas are globally one of the major sources of toxic metals. Nowadays, no method can guarantee an immediate response for quantifying these pollutants. In this work, a novel technique based on microwave spectroscopy and planar sensors for in situ real-time monitoring of water quality is described. The sensors were developed to directly probe water samples, and in situ trial measurements were performed in freshwater in four polluted mining areas in the UK. Planar microwave sensors were able detect the water pollution level with an immediate response specifically depicted at three resonant peaks in the GHz range. To the authors’ best knowledge, this is the first time that planar microwave sensors were tested in situ, demonstrating the ability to use this method for classifying more and less polluted water using a multiple-peak approach.

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Experimental Testing of Vibration Analysis Methods to Monitor Recovery of Stiffness of a Fixated Synthetic Pelvis: A Preliminary Study

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.558.386 ◽

2013 ◽

Vol 558 ◽

pp. 386-399 ◽

Cited By ~ 6

Author(s):

Lydia Chwang Yuh Wong ◽

Wing Kong Chiu ◽

Matthias Russ ◽

Susan Liew

Keyword(s):

Vibration Analysis ◽

Transfer Functions ◽

Experimental Testing ◽

Experimental Tests ◽

In Situ Monitoring ◽

Long Bone ◽

Healing Fracture ◽

Cure Time ◽

Preliminary Study

Monitoring the healing of long bones has been studied extensively to reduce the period of encumbrance and unnecessary pain for patients suffering from fractured bones. This is more critical for unstable fractures in the pelvis as the patients can bedridden for up to 12 weeks to allow proper healing to take place. Current methods employed to monitor long bone healing are insufficient for applications in the pelvis as the human pelvis presents a significant change in geometry which demands a different approach. This paper explores an approach where vibration analysis is used to provide in-situ monitoring of a healing fracture in a human pelvis. Experimental tests were conducted on 4th generation synthetic pelvises instrumented with an array of PZT sensors. The synthetic pelvises were cut at the sacrum to simulate a fractured pelvis followed by the application of araldite epoxy to simulate healing by allowing the epoxy to cure. Measurements were collected from the sensor array over the curing period to obtain the transfer functions (TFs) for various excitations. An impact hammer was utilised to obtain powerful broadband excitations while the PZT sensors were used to detect the response in the synthetic pelvis as a results of these excitation signals. A comparison of TF against cure time (healed amount) indicates the presence of a significant relationship with the stiffness recovery of the epoxy at the cut of the synthetic model.

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