scholarly journals METHOD FOR DETECTING DEFECTS IN MARINE PIPELINES BY WAVELET ANALYSIS OF REMOTE MAGNETOMETRY SIGNAL

2020 ◽  
pp. 133-142
Author(s):  
Vitaly A. Veselov ◽  
Vladimir V. Probotyuk ◽  
Maksim V. Kitaev ◽  
Oleg E. Surov
Keyword(s):  
Magnetic Field ◽  
Wavelet Transform ◽  
Pipe Wall ◽  
Technical Condition ◽  
Suggested Method ◽  
Engineering Analysis ◽  
Analysis Software ◽  
Offshore Pipelines ◽  
The Magnetic Field ◽  
Corrosion Spot

The paper considers a method for detecting offshore pipelines defects using a wavelet transform of a remote magnetometry signal. This method makes it easier and faster to process large amounts of information obtained as the measuremens result. According to statistics, 40% to 50% of accidents with offshore pipelines occur due to the pipe walls corrosion. Thus, the research aimed to development the methods for offshore pipelines inspection and diagnostics is very important. For the testing of the suggested method for detecting pipeline defects, on the engineering analysis software ELCUT base a numerical model describing the magnetic field distribution in the area of corrosion spot located on the pipe wall was developed. It is shown that the suggested method can be used for detecting the defects and evaluating the offshore pipelines technical condition.

Experimental Research on the Magnetic Field Sensitive Polymeric Actuator

2011 ◽  
Vol 287-290 ◽  
pp. 603-607
Author(s):  
Chun Lin Xia ◽  
Yang Fang Wu ◽  
Qian Qian Lu
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Energy Conversion ◽  
Experimental Research ◽  
Experimental Results ◽  
Deformation Characteristics ◽  
Analysis Software ◽  
Element Analysis ◽  
The Magnetic Field

Using domestic MFSP membrane as a medium of energy conversion, a kind of MFSP actuator was designed. The dedicated test equipment was constructed for experimental research, and the experimental results were given. The strip and circular MSFP membrane were analyzed qualitatively to obtain the deformation characteristics of membrane by finite element analysis software.

Development of Numerical Analysis Software for the NDE by Using Dipole Model

2007 ◽  
Vol 353-358 ◽  
pp. 2383-2386
Author(s):  
Jin Yi Lee ◽  
Jong Woo Jun ◽  
Ji Seong Hwang ◽  
Se Hoon Lee
Keyword(s):  
Magnetic Field ◽  
Numerical Analysis ◽  
Field Distribution ◽  
Electrical Signal ◽  
Dipole Model ◽  
Magnetic Field Distribution ◽  
Analysis Software ◽  
Magnetization Direction ◽  
Lift Off ◽  
The Magnetic Field

The magnetic field distribution around a crack can be calculated more easily and quickly by using a dipole model than finite element method (FEM). This paper reports the development of numerical analysis software that uses an improved dipole model to analyze the magnetic field around cracks. The preprocessor in this software includes the crack formation software, which can distribute the magnetic charge per unit area, m, on the crack section area. Also the lift-off, measurement area and sensor interval, and magnetization direction can be considered in the preprocessor. Also, the postprocessor presents functions, such as the natural magnetic field distribution and ∂B/∂x, ∂B/∂y, as results. Also, the physical characteristics of the magnetic optical sensor and the Hall sensor are included in the postprocessor, and the magnetic field distribution can be changed to optical intensity and electrical signal distribution. The experiment results, which are obtained by using the magnetic camera on the crack, are compared with analysis results obtained by using the dipole model analysis software.

Challenges in Circumferential Magnetisation II: A FEA Point of View

2006 ◽  
Author(s):  
R. C. Ireland ◽  
C. R. Torres
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Wall Thickness ◽  
Pipe Wall ◽  
Point Of View ◽  
Field Profile ◽  
Pipe Wall Thickness ◽  
Magnetic Field Profile ◽  
Background Magnetic Field ◽  
The Magnetic Field

In order to design a Magnetic Flux Leakage (MFL) tool, knowledge of the magnetic field profile both within the pipe wall and around the sensor locations is required. The former is important since the magnitude of a defect signature will be maximised when the pipe wall is magnetically saturated. The latter is important for the reason that the background magnetic field profile will determine the sensor bias level for a given defect. Previous research using the Finite Element (FE) technique has investigated the magnetic field profile within the pipe wall for a generic circumferential MFL tool and showed how it varied depending upon the pipe wall thickness and tool speed. It was found that as the pipe wall thickness and tool speed increased, a plume of magnetic flux formed behind the tool. Furthermore, it was observed that as the pipe wall thickness increased, outer regions of the pipe wall exhibited substantially reduced levels of magnetic flux. A reduction of magnetic flux in these outer regions of the pipe wall suggests defects located here may be harder to detect and resolve compared to defects located closer to the inner pipe wall. This paper briefly reviews the previous research and extends the numerical analysis by considering the magnitude of the magnetic field profile for locations within the inner and outer pipe wall and possible sensor positions. It is shown how these profiles change with pipe wall thickness and tool speed and demonstrates the complex and non-linear nature of the magnetic field. The information obtained can be combined with previous research and will be useful for determining the optimal sensor location and yield predictions for background magnetic field magnitudes. The full complexity of magnetic materials is not incorporated into the modelling, however, the results obtained give a theoretical indication of operational limitations of the circumferential MFL technique.

Microfluidic Biosensing Method Using the Motion of Magnetic Microparticles

2014 ◽  
Vol 605 ◽  
pp. 348-351 ◽  
Author(s):  
Georgios Kokkinis ◽  
Alexander Dangl ◽  
Franz Keplinger ◽  
Ioanna Giouroudi
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Microfluidic Channel ◽  
Proof Of Concept ◽  
Analysis Software ◽  
Element Analysis ◽  
Velocity Change ◽  
Magnetic Microparticles ◽  
New Compounds ◽  
The Magnetic Field

In this paper a microfluidic biosensing method for detecting a bioanalyte using the motion of magnetic microparticles (MPs) is presented. The system consists of a microfluidic channel, in which the MPs are suspended and current carrying microconductors positioned underneath the channel. These microconductors are used in order to move the MPs from the inlet to the outlet of the channel. The MPs are functionalized by modifying their surface, thus enabling them to chemically bind to a specific (non-magnetic) bioanalyte. Once the MPs binds to the bioanalyte new compounds are formed (LMPs). These compounds have a bigger overall volume than the bare MPs but still the same magnetic volume. The MPs and LMPs are manipulated inside the microfluidic channel by exposing them to magnetic field generated by the microconductors. When both, MPs and LMPs, are accelerated by the same magnetic field density, the LMPs are going to be slower than the MPs due to their increased (non-magnetic) volume. This difference in velocity is used to discriminate between MPs and LMPs. Calculations concerning the velocity change of MPs and the magnetic field generated by the current carrying microconductors were carried out. Simulations of various geometries for the conductors and various MPs were performed using finite element analysis software. Several chips were fabricated and experiments with different MPs and LMPs were conducted as a proof of concept.

Separation and Recycling Non-Magnetic Metals from the Shredded Automobiles Scrap with Magnetic Fluids

2011 ◽  
Vol 233-235 ◽  
pp. 470-475
Author(s):  
Hui Ping Shao ◽  
Tao Lin ◽  
Ji Luo ◽  
Zhi Meng Guo
Keyword(s):  
Magnetic Field ◽  
Software Package ◽  
Magnetic Fluids ◽  
Analysis Software ◽  
Element Analysis ◽  
Field System ◽  
Water Based ◽  
The Magnetic Field ◽  
Nonmagnetic Metals ◽  
Chemical Coprecipitation Method

It is important to separate the nonmagnetic metals from shredded automobiles scraps efficiently. The research relates in general to the separation of non-magnetic metals automatically on the basis of the different density of the magnetic fluids in a magnetic field. A water-based magnetic fluid was prepared with a chemical coprecipitation method by using ultrasonic in dispersing process. The magnetic field system was design and simulated by a finite element analysis software package, ANSYS 8.1. Separation tests were performed on the mixtures of aluminum, zinc, copper and lead with various scrap size and shape using the water-based magnetic fluids.

scholarly journals Extraction of Magnetic Field Features to Determine the Degree of Material Strain

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1576
Author(s):  
Przemysław Szulim ◽  
Szymon Gontarz
Keyword(s):  
Magnetic Field ◽  
Technological Development ◽  
Steel Structures ◽  
Extraction Process ◽  
Diagnostic Techniques ◽  
Technical Condition ◽  
Technical Diagnostics ◽  
Material Condition ◽  
Diagnostic Symptoms ◽  
The Magnetic Field

Currently, to realize the reliable operation and proper exploitation of complex machines and structures, information regarding the material condition must be obtained. This information should ideally be acquired in a noninvasive manner. In addition, contemporary rapid technological development is conducive to the research and advancement of new methods, including magnetic methods. This publication describes the methods that can enable the extraction of information from the magnetic field, which is valuable for determining the material effort state and performing technical diagnostics. The issue of using the magnetic field to assess the technical condition of structures is a promising trend in technical diagnostics. Moreover, new ways to process the magnetic field information are being identified to connect the observed surface changes in the magnetic field with the significant diagnostic symptoms. This work provides an extensive introduction to the theoretical basis and diagnostic techniques based on measurements of the magnetic field obtained in close proximity to the structure of interest. The key limitations of the method and associated possibilities are highlighted. The model considerations were taken into account to provide a mathematical description of the extraction process and possible interpretations of the acquired signals. According to the received guidelines, the plan and implementation of two experiments are described along with the obtained results, which demonstrated the possibility of identifying valuable information that can be used to determine the state of the material stress and perform diagnostics of steel structures.

Observing the galactic magnetic field

1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst
Keyword(s):  
Magnetic Field ◽  
Fair Agreement ◽  
Solar Neighbourhood ◽  
Galactic Magnetic Field ◽  
The Magnetic Field

Various methods of observing the galactic magnetic field are reviewed, and their results summarized. There is fair agreement about the direction of the magnetic field in the solar neighbourhood:l= 50° to 80°; the strength of the field in the disk is of the order of 10-5gauss.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

On the Configuration of the Magnetic Field of β CrB

1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Radial Velocity ◽  
Magnetic Field Strength ◽  
Complex Shape ◽  
Rotation Period ◽  
Field Variation ◽  
Magnetic Field Variation ◽  
Secular Variations ◽  
The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

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