scholarly journals Experimental Study of the Corona Performance of Aged Sand-Cast Substation Connectors

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2785
Author(s):  
Jordi-Roger Riba ◽  
Santiago Bogarra ◽  
Álvaro Gómez-Pau ◽  
Manuel Moreno-Eguilaz
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Salt Spray ◽  
Ageing Effect ◽  
Cast Aluminum ◽  
Spray Chamber ◽  
Clear Pattern ◽  
Sand Cast ◽  
Ageing Period

Substation connectors, like many other high-voltage products, are tested once manufactured. However, the corona behavior of aged specimens can differ from that exhibited by newer ones, thus generating detrimental technical and environmental effects. Manufacturers need to know the long-term corona behavior of substation connectors to offer their customers maximum safety and transparency about such critical products. This paper analyzes the ageing effect on the surface roughness and the visual corona extinction voltage of sand-cast aluminum connectors, which were artificially aged in a salt spray chamber for different periods. The experimental results show an important variability of the surface roughness and corona extinction voltage (CEV) among connectors with the same ageing level due to the sand-casting manufacturing process. The results in this paper also show a slight increase in the surface roughness with the ageing period, although there is not a clear pattern between the applied ageing level and the experimental CEV value. It is concluded that the inherent variability among connectors due to the sand-cast process has more influence than the ageing effect itself.

Experimental study on the long-term stability of shale rock wellbore under high hydraulic pressure

2021 ◽  
Vol 14 (3) ◽  
Author(s):  
Baoyun Zhao ◽  
Xiaoping Wang ◽  
Wei Huang ◽  
Tianzhu Huang ◽  
Yang Liu
Keyword(s):  
Experimental Study ◽  
Hydraulic Pressure ◽  
Term Stability ◽  
Long Term Stability ◽  
Shale Rock

scholarly journals The Influence of Surface Preparation of the Steel during the Renovation of the Car Body on Its Corrosion Resistance

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 384
Author(s):  
Dariusz Ulbrich ◽  
Jakub Kowalczyk ◽  
Arkadiusz Stachowiak ◽  
Wojciech Sawczuk ◽  
Jaroslaw Selech
Keyword(s):  
Corrosion Resistance ◽  
Glass Bead ◽  
Salt Spray ◽  
Zinc Coating ◽  
Surface Preparation ◽  
The Other ◽  
Average Thickness ◽  
Spray Chamber ◽  
Car Body ◽  
Abrasive Blasting

The article presents the influence of the applied method used for removing the varnish coat on the corrosion resistance of the car body sheet. The tests were carried out on samples prepared from factory-painted car body elements with pearlescent, metallized and acrylic varnish. Removal of the varnish coat was performed by sandpaper grinding, glass bead blasting, disc blaze rapid stripping, soda blasting and abrasive blasting with plastic granules. The average thickness of the factory-painted coating depending on the type of lacquer ranged from about 99 to 140 µm. On the other hand, after removing the varnish, the thickness of the protective zinc coating ranged from 2 to 12.7 µm. The highest values of the zinc coating were obtained for samples in which the varnish was removed by the method such as soda blasting and abrasive blasting with plastic granules. For these two methods of surface preparation, the damage to the zinc layer protecting the steel against corrosion is the smallest and the percentage of zinc in the surface layer ranges from 58% to 78%. The final stage of the research was to test the samples after removing the varnish coat in a two-hour exposure to the corrosive environment in a salt spray chamber. Samples with the surface prepared by grinding with sandpaper reached the level of surface rusting Ri 5, while in the case of soda blasting and the use of plastic granules, no corrosion centers were observed on the surface of the car body sheet.

scholarly journals Performance of Norton Quantum Grinding Wheels

2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Removal Rates ◽  
Surface Burn ◽  
Conventional Grinding

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.

Long-Term Mechanical Stability of the Impacted Morselized Graft-Cement Interface in Total Joint Replacement: An Experimental Study in Dogs

Orthopedics ◽  
2000 ◽  
Vol 23 (8) ◽  
pp. 809-814
Author(s):  
Konstantinos G Stamos ◽  
Theophilos Karachalios ◽  
Panayiotis J Papagelopoulos ◽  
Theodore Xenakis ◽  
Demetrios S Korres ◽  
...  
Keyword(s):  
Experimental Study ◽  
Joint Replacement ◽  
Mechanical Stability ◽  
Total Joint Replacement ◽  
Cement Interface
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