Magnetic Barkhausen Noise Testing for Subsurface Discontinuities under DC Magnetization

2020 ◽  
Vol 78 (12) ◽  
pp. 1310-1318
Author(s):  
Chenyong Liu ◽  
Jianbo Wu ◽  
Song Ding ◽  
Zihan Wang ◽  
Yunfei Zhang
Keyword(s):  
Domain Walls ◽  
High Sensitivity ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Near Surface ◽  
Dc Magnetization ◽  
Ship Hulls ◽  
Nondestructive Testing Methods ◽  
Oil Tanks

Subsurface discontinuities are inevitably formed during the long-term operations of pipelines, oil tanks, ship hulls, and the like. However, it is still a big challenge to detect deeply buried subsurface discontinuities using existing nondestructive testing methods. In this paper, based on the high sensitivity of magnetic Barkhausen noise (MBN) to the movement of the domain walls, an MBN test under direct current (DC) magnetization is proposed for subsurface discontinuity detection. Under DC magnetization, subsurface discontinuities will distort the magnetic field distribution in the near-surface layer of the specimen and then affect the movement of the domain walls in this region. Meanwhile, through alternating current (AC) excitation, MBN testing is conducted to detect the movement of the domain walls to evaluate subsurface discontinuities. To validate the proposed technique, MBN experiments under DC magnetization are conducted to quantify subsurface discontinuities with different buried depths. Experimental results indicate that the proposed technique can detect subsurface discontinuities with buried depths of up to 5 mm, and the extracted MBN energy feature has an approximately linear relationship with the buried depth.

Evaluating Temper Embrittlement in HY-80 Steel Using Magnetic Barkhausen Noise and Microstructural Characterization

2021 ◽  
Author(s):  
Michael Roberts ◽  
Charles D’Ambra ◽  
Jason Schibler ◽  
Michele Manuel ◽  
Thomas W. Krause ◽  
...  
Keyword(s):  
Domain Walls ◽  
Temper Embrittlement ◽  
Low Carbon Steel ◽  
High Strength ◽  
Microstructural Characterization ◽  
Holding Time ◽  
Barkhausen Noise ◽  
Low Carbon ◽  
Magnetic Barkhausen Noise ◽  
Destructive Testing

Abstract HY80 steel is a low-carbon steel known for embodying high strength and toughness properties. This steel is used in submarine applications. Temper embrittlement, which is the reduction of fracture toughness, occurs in steels when subject to aging and drastic temperature fluctuations. These changes occur in submarines over time while in underwater environments. During temper embrittlement, impurity atoms and carbides migrate to grain boundaries, which make the steel more susceptible to fracture. A non-destructive testing (NDT) method is desirable to assess the temper embrittlement damage in HY80. Magnetic Barkhausen Noise (MBN) is of interest as being a potential NDT method for analyzing HY80. Focusing on microstructural characterization and its effect on MBN could have implications for establishing an MBN based method to detect varied stages of temper embrittlement in HY80 steel. In this research, samples of HY80 were prepared and heat treated for 16–336 hours to mimic various degrees of temper embrittlement. Microstructural changes with heat treatment were characterized and connected to the MBN produced at each holding time. Methods consisted of performing scanning electron microscopy (SEM) and using an MBN measurement system. It was observed that as holding time increases, grain size increases and carbide density within the grains decreases. These carbides, which act as pinning sites, make it more difficult for domain walls to move, consequently affecting MBN energy.

scholarly journals Time-Response-Histogram-Based Feature of Magnetic Barkhausen Noise for Material Characterization Considering Influences of Grain and Grain Boundary under In Situ Tensile Test

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2350
Author(s):  
Jia Liu ◽  
Guiyun Tian ◽  
Bin Gao ◽  
Kun Zeng ◽  
Yongbing Xu ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Tensile Stress ◽  
Material Properties ◽  
Ferromagnetic Material ◽  
Silicon Steel ◽  
Time Response ◽  
Barkhausen Noise ◽  
Time Interval ◽  
Magnetic Barkhausen Noise

Stress is the crucial factor of ferromagnetic material failure origin. However, the nondestructive test methods to analyze the ferromagnetic material properties’ inhomogeneity on the microscopic scale with stress have not been obtained so far. In this study, magnetic Barkhausen noise (MBN) signals on different silicon steel sheet locations under in situ tensile tests were detected by a high-spatial-resolution magnetic probe. The domain-wall (DW) motion, grain, and grain boundary were detected using a magneto-optical Kerr (MOKE) image. The time characteristic of DW motion and MBN signals on different locations was varied during elastic deformation. Therefore, a time-response histogram is proposed in this work to show different DW motions inside the grain and around the grain boundary under low tensile stress. In order to separate the variation of magnetic properties affected by the grain and grain boundary under low tensile stress corresponding to MBN excitation, time-division was carried out to extract the root-mean-square (RMS), mean, and peak in the optimized time interval. The time-response histogram of MBN evaluated the silicon steel sheet’s inhomogeneous material properties, and provided a theoretical and experimental reference for ferromagnetic material properties under stress.

scholarly journals Draft Genome Sequences of Four Alteromonas macleodii Strains Isolated from Copper Coupons and Grown Long-Term at Elevated Copper Levels: TABLE 1 

2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Kathleen D. Cusick ◽  
Jason R. Dale ◽  
Brenda J. Little ◽  
Justin C. Biffinger
Keyword(s):  
Marine Bacterium ◽  
Draft Genome ◽  
Genome Sequences ◽  
Ship Hulls ◽  
Early Stages ◽  
Antifouling Agent ◽  
Alteromonas Macleodii

Alteromonas macleodii is a marine bacterium involved in the early stages of biofouling on ship hulls treated with copper as an antifouling agent. We report here the draft genome sequences of an A. macleodii strain isolated from copper coupons and three laboratory mutants grown long-term at elevated copper levels.

Long-term performance of zeolite Na A-X blend as backfill material in near surface disposal vault

2009 ◽  
Vol 149 (1-3) ◽  
pp. 143-152 ◽  
Author(s):  
R.O. Abdel Rahman ◽  
H.A. Ibrahim ◽  
N.M. Abdel Monem
Keyword(s):  
Near Surface ◽  
Backfill Material ◽  
Long Term Performance ◽  
Term Performance

Near-infrared persistent luminescence hollow mesoporous nanospheres for drug delivery and in vivo renewable imaging

2016 ◽  
Vol 4 (48) ◽  
pp. 7845-7851 ◽  
Author(s):  
Junpeng Shi ◽  
Meng Sun ◽  
Xia Sun ◽  
Hongwu Zhang
Keyword(s):  
Drug Delivery ◽  
Near Infrared ◽  
High Sensitivity ◽  
Drug Carriers ◽  
Template Method ◽  
Persistent Luminescence ◽  
Deep Tissue ◽  
Large Capacity

Near-infrared persistent luminescence hollow mesoporous nanospheres have been synthesized via a template method. These nanospheres can be used as large capacity drug carriers and realize super long-term and high sensitivity tracking of drug delivery in deep tissue.

scholarly journals Patients With a History of Idiopathic Deep Venous Thrombosis Have Long-Term Increased Levels of Inflammatory Markers and Markers of Endothelial Damage

2016 ◽  
Vol 23 (2) ◽  
pp. 124-131 ◽  
Author(s):  
Mateja Kaja Jezovnik ◽  
Jawed Fareed ◽  
Pavel Poredos
Keyword(s):  
Inflammatory Markers ◽  
High Sensitivity ◽  
Endothelial Damage ◽  
Control Group ◽  
Necrosis Factor Alpha ◽  
Reactive Protein ◽  
Inflammatory Parameters ◽  
History Of ◽  
Hemostatic Markers

Introduction: Although the role of inflammation in DVT has been investigated in different studies, there is no definite answer as to whether increased systemic inflammation is the cause or the consequence of DVT. Aim: To follow inflammatory parameters in a cohort of patients with idiopathic DVT. Methods: Out of 49 patients with an acute idiopathic DVT, which were investigated four months after an acute episode (DEVTA 1), 43 patients were included in the follow-up study investigating inflammatory markers and hemostatic markers of endothelial damage five years after an acute DVT (DEVTA 2). A control group consisted of 43 sex and age matched healthy subjects (CONTROLS). Results: The levels of inflammatory markers were significantly higher in DEVTA 2 in comparison to CONTROLS: tumor necrosis factor alpha 2.0 pg/mL (1.1-2.3) vs 1.3 pg/mL (0.8-1.9), p < .001, high sensitivity C-reactive protein 3.2 mg/L (1.5-5.2) vs 1.7 mg/L (0.9-3.0), p = .008, interleukin-6 (IL-6) 2.7 pg/mL (2.0-3.5) vs 2.1 pg/mL (1.5-2.6), p = .025, IL-8 5.0 pg/mL (3.6-7.3) vs 2.4 pg/mL (1.8-2.8), p < .001. IL-10 was significantly decreased (0.9 pg/mL (0.7-1.8) vs 1.8 (1.5-2.2), p < .001. Most of the proinflammatory markers remained elevated in the DEVTA 2 in comparison to DEVTA 1. Markers of endothelial damage were higher in DEVTA 2 in comparison to CONTROLS and higher than in DEVTA 1. Conclusion: Patients with idiopathic DVT have long-term increased inflammatory markers and markers of endothelial damage. These findings favor the hypothesis that inflammation is a cause and not merely a consequence of acute DVT.

scholarly journals Short- and Long-term Biologic Variability of Galectin-3 and Other Cardiac Biomarkers in Patients with Stable Heart Failure and Healthy Adults

2016 ◽  
Vol 62 (2) ◽  
pp. 360-366 ◽  
Author(s):  
Emily I Schindler ◽  
Jeffrey J Szymanski ◽  
Karl G Hock ◽  
Edward M Geltman ◽  
Mitchell G Scott
Keyword(s):  
Heart Failure ◽  
Troponin I ◽  
Prognostic Biomarker ◽  
High Sensitivity ◽  
Cardiac Biomarkers ◽  
Healthy Individuals ◽  
Short Term ◽  
Galectin 3 ◽  
Short And Long Term

Abstract BACKGROUND Galectin-3 (Gal-3) has been suggested as a prognostic biomarker in heart failure (HF) patients that may better reflect disease progression than traditional markers, including B-type natriuretic peptide (BNP) and cardiac troponins. To fully establish the utility of any biomarker in HF, its biologic variability must be characterized. METHODS To assess biologic variability, 59 patients were prospectively recruited, including 23 male and 16 female patients with stable HF and 10 male and 10 female healthy individuals. Gal-3, BNP, and high-sensitivity cardiac troponin I (hs-cTnI) were assayed at 5 time points within a 3-week period to assess short-term biologic variability. Long-term (3-month) biologic variability was assessed with samples collected at enrollment and after 4, 8, and 12 weeks. RESULTS Among healthy individuals, mean short-term biologic variability, expressed as intraindividual CV (CVI), was 4.5% for Gal-3, 29.0% for BNP, and 14.5% for hs-cTnI; long-term biologic variability was 5.5% for Gal-3, 34.7% for BNP, and 14.7% for hs-cTnI. In stable HF patients, mean short-term biologic variability was 7.1% for Gal-3, 22.5% for BNP, and 8.5% for hs-cTnI, and mean long-term biologic variability was 7.7% for Gal-3, 27.6% for BNP, and 9.6% for hs-cTnI. CONCLUSIONS The finding that Gal-3 has minimal intraindividual biological variability adds to its potential as a useful biomarker in HF patients.

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