scholarly journals Failure Analysis of Clamp Crack on TA Equipment in Converter Station

2020 ◽  
Vol 165 ◽  
pp. 06052
Author(s):  
Jun Wang ◽  
Junling Tan ◽  
Jun Liu ◽  
Jie Gong ◽  
Jiarui Hu ◽  
...  
Keyword(s):  
Performance Test ◽  
Hardness Test ◽  
Composition Analysis ◽  
Scanning Electron Microscope Analysis ◽  
Tensile Performance ◽  
Electron Microscope Analysis ◽  
Chemical Composition Analysis ◽  
Selection Of ◽  
Scanning Electron

Through macro inspection, chemical composition analysis, hardness test, tensile performance test, microstructure inspection and scanning electron microscope analysis, the causes of clamp crack on TA equipment in the 500kV AC filter field of the ± 800kV converter station were analyzed. The results show that improper selection of the manufacturing process of the equipment clamps will cause more micro-defects inside it, leading to poor mechanical properties and excessive internal stress, which are the main causes of cracking. Corresponding measures are put forward to improve the manufacturing quality of equipment clamps, which can avoid similar failures from happening again.

scholarly journals Failure Analysis of Weld Cracking in External Cold Water Pipeline of Condenser in Converter Station

2020 ◽  
Vol 165 ◽  
pp. 06031
Author(s):  
Jun Wang ◽  
Yaxia Qiao ◽  
Hao Zhang ◽  
Hongjian Lou
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cold Water ◽  
Welding Process ◽  
Hardness Test ◽  
Control Measures ◽  
Composition Analysis ◽  
Chemical Composition Analysis ◽  
Water Pipeline ◽  
Scanning Electron

The cause of weld cracking in external cold water pipeline of condenser in a ±800kV converter station were analyzed by macro inspection, chemical composition analysis, hardness test, microstructure inspection, scanning electron microscopy and energy spectrum test methods.The results show that the main reason for the cracks is that the material and manufacturing process are not qualified, and the welding process is not good. Corresponding control measures are put forward to avoid similar failures from happening again.

scholarly journals Susceptibility Assessment of Multidrug Resistant Bacteria to Natural Products

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582093618
Author(s):  
Essam Hassan Mohamed ◽  
Youssef Saeed Alghamdi ◽  
Salama Mostafa Abdel-Hafez ◽  
Mohamed Mohamed Soliman ◽  
Saad H. Alotaibi ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Syzygium Aromaticum ◽  
Bacterial Strains ◽  
Multidrug Resistant Bacteria ◽  
Scanning Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Holothuria Atra ◽  
Scanning Electron

Objective: The aim of this study was to examine the effect of some natural compounds against multidrug-resistant bacteria. Methods: Forty-three bacterial strains were collected. Disc diffusion and minimum inhibitory concentration (MIC) tests were carried out for natural compounds including quercetin, Acacia nilotica, Syzygium aromaticum, and Holothuria atra. Scanning electron microscope analysis and bacterial DNA apoptosis assays were performed. Results: Staphylococcus aureus strains were resistant to imipenim, ampicillin, and penicillin. Most Escherichia coli strains were resistant to amoxicillin, clavulanat, and ampicillin. Finally, tigecycline was effective with Klebsiella pneumoniae and was resistant to all antibiotics. Only S aromaticum had an antibacterial effect on K pneumoniae. Most S aureus strains were sensitive to S aromaticum, A nilotica, and quercetin. All examined natural extracts had no effect on E coli. Holothuria atra had no effect on any of the strains tested. Minimum inhibitory concentration and minimum bactericidal concentration values for examined plants against S aureus were 6.25 to 12, 1.6 to 3.2, and 9.12 to 18.24 mg/mL, respectively. Syzygium aromaticum was active against K pneumoniae with an MIC of 12.5 mg/mL. Scanning electron microscope analysis performed after 24 and 48 hours of incubation showed bacterial strains with distorted shapes and severe cell wall damage. Syzygium aromaticum, quercetin, and A nilotica showed clear fragmentations of S aureus DNA. Conclusions: Current findings confirmed the beneficial effect of using natural products such as clove (S aromaticum), quercetin, and A nilotica as a promising therapy to overcome multidrug resistant bacteria.

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