Top PDF System and method for non-destructive evaluation of surface characteristics of a magnetic material

System and method for non destructive evaluation of surface characteristics of a magnetic material

System and method for non destructive evaluation of surface characteristics of a magnetic material

A system and a related method for non-destructive evaluation of the surface characteristics of a magnetic material. The sample is excited by an alternating magnetic field. The field frequency, amplitude and offset are controlled according to a predetermined protocol. The Barkhausen response of the sample is detected for the various fields and offsets and is analyzed. The system produces information relating to the frequency content, the amplitude content, the average or RMS energy content, as well as count rate information, for each of the Barkhausen responses at each of the excitation levels applied during the protocol. That information provides a contiguous body of data, heretofore unavailable, which can be analyzed to deduce information about the surface characteristics of the material at various depths below the surface.
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Method of Non Destructive Geophysical Mapping of the Environment

Method of Non Destructive Geophysical Mapping of the Environment

The new approach, which forms the basis of an integrated seismic and electromagnetic research method, has shown its viability and practical significance in the study of rock massifs of various material compositions. Seismic and electromagnetic information is mutually complementary in the mapping and prediction of the behavior of an array that is under technogenic influence. It relies on the use of active methods of geophysical monitoring using controlled concentrated sources of excitation, allowing spatial movement along a given observation system with overlapings. The complex technique has a high resolution that does not concede to tomographic studies, and the created software allows you to restore the volume geoelectric and seismic model of the array, which is used to calculate the volume distribution of the stress tensor in the array [23] [41] [42]. The implementation of the technique can, with a decrease in the excited and measured frequencies of an alternating magnetic field with a given detail, either directly map the structure of the hydrocarbon deposit, or use the detailed seismic information on these zones for setting indus- trial wells with a sharp reduction in additional preliminary drilling. Currently, such equipment is available in the IGF UB RAS. The developed planshet induc- tion technique using a controlled source of excitation was included in the com- plex of electromagnetic methods used in the Arab Republic of Egypt for solving problems of shallow geophysics and archeology [43] [44].
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Non-Destructive Evaluation of Concrete Structures by Non-Stationary Thermal Wave Imaging

Non-Destructive Evaluation of Concrete Structures by Non-Stationary Thermal Wave Imaging

Applicability of the proposed excitation method for IR non-destructive testing is experimentally tested on a reinforced concrete sample shown on Figure 1. Experiments have been carried out on a concrete specimen of 6.7 cm thickness and contain 4 cm thickness mild steal rebar of length 13.24 cm. In order to study the corrosion detection capabilities of the frequency modulated thermal wave imaging in rebar in concrete structures, an artificial corrosion has been simulated to the rebar as shown on Figure 1 by introducing four grove cuts of different widths (a, b, c and d) with a material loss of 5 mm from the surface of bar.
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Evaluation of Defects in the SS 304l Material by using Non Destructive Examination Techniques

Evaluation of Defects in the SS 304l Material by using Non Destructive Examination Techniques

Whilst being a high technology concept, evolution of the equipment has made it robust enough for application in any industrial environment at any stage of manufacture - from steelmaking to site inspection of components already in service. A certain degree of skill is required to apply the techniques properly in order to obtain the maximum amount of information concerning the product, with consequent feed back to the production facility. Non-destructive Testing is not just a method for rejecting substandard material. The technique uses a variety of principles. On-destructive Testing is one part of the function of Quality Control and is complementary to other long established methods. By definition non-destructive testing is the testing of materials, for surface or internal flaws or metallurgical condition, without interfering in any way with the integrity of the material or its suitability for service.
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Non Destructive Evaluation of Material System Using Highly Nonlinear Acoustic Waves

Non Destructive Evaluation of Material System Using Highly Nonlinear Acoustic Waves

an empirical dissipative term which depends on the relative velocities between adjacent particles. The exponents and prefactors of the dissipative terms were determined using an optimization scheme. In the FEM, we included linear Rayleigh damping parameters and used root-mean-square deviation to obtain the optimized mass-proportional damping factor. The experimental results were found to be in good agreement with the proposed analytical and finite element models in terms of capturing the evolution of the wave amplitude and wave shape in time. The experimental results showed that when the particles composing the chain are made of soft material, like rubber, PTFE, etc, the disspative effects not only affect the wave amplitude, but it also affects the wave shape too. The current model only used the mass proportional damping effects, it is not capable of capturing the complete wave form, especially when the particles composing the chains are highly dissipative or viscous. The addition of stiffness proportional damping effects will provide additional degree of freedom in capturing both wave amplitude and wave shape for highly damped system, nevertheless, since the dissipative modeled used in finite element method is linear in nature, it may not be able to capture the overall nonlinear effects of energy losses.
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A system identification based approach for pulsed eddy current non-destructive evaluation

A system identification based approach for pulsed eddy current non-destructive evaluation

NDE can be applied on-line as shown in Figure 2 to determine the defective or working condition of an inspected system or structure from the system or structure’s response to a pulse excitation. The pulsed excitation and the corresponding eddy current sensor response measured from the system or structure are first used to determine a transfer function model of the system or structure. Then the FDA is applied to extract the features of the system or structure from the estimated transfer model parameters. Finally, the maximum selection process is applied to the results evaluated from p Fisher discriminative functions, and the class of defective or working condition that corresponds to the maximum Fisher discriminative function value is assigned to the system or structure under inspection. It is well-known that the defective or working conditions of systems or structures are essentially determined by the systems or structural integrity characteristics. For example, in metal structures, these conditions are determined by microstructures, surface form and roughness, natural crack, residual stress beyond tradition discontinuity crack, and corrosion etc many factors. Conventional NDE techniques depend directly on sensor measurement signals to perform analysis and to conduct pattern classification. However, any direct measurement from NDE oriented tests can only reflect these material characteristics indirectly, and the measurement results also unavoidably prone to the effects of measurement errors and noises. For example, although the distinctive advantage of pulsed eddy current NDE is that the measured signal covers a wide range of spectrum so as to be able to reflect defects of different depths, the unavoidable high frequency noise effects on the measured wideband signals may not be negligible and may consequently impair the NDE results.
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NON-DESTRUCTIVE TESTS OF LOCK TONGUES USED IN ATR-72 AIRCRAFT LANDING GEAR BASED ON MAGNETIC METHOD

NON-DESTRUCTIVE TESTS OF LOCK TONGUES USED IN ATR-72 AIRCRAFT LANDING GEAR BASED ON MAGNETIC METHOD

Cleaning the tested object from all kinds of waste, such as grease, dirt, oils and anticorrosive countermeasures is a crucial step in the testing process. In particular anticorrosive paints with ferromagnetic characteristics must not be left on the object. The object in question was first cleaned with a cloth wetted in special clearing salve, and then placed in an ultrasonic cleaner. Overall clean- ing took 30 minutes. Next the researches proceed- ed to initial inspection of the tested object. The purpose of this test phase is to locate any defects which were revealed after the cleaning process was complete. The initial evaluation was conduct- ed using magnifying glass in 5× magnification. The test did not reveal any defects so the research- es proceeded to the next step. This stage involves demagnetization of the component in laboratory conditions using a demagnetizer so that the resid- ual magnetism does not exceed 500 A/m. By de- fault, residual magnetism of the tested object was 600 A/m. After demagnetization the levels of the object’s magnetism decreased to 100 A/m.
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INFLUENCE OF SURFACE ROUGHNESS ON NON-DESTRUCTIVE MAGNETIC MEASUREMENTS.

INFLUENCE OF SURFACE ROUGHNESS ON NON-DESTRUCTIVE MAGNETIC MEASUREMENTS.

During the measurement, the performance characteristics of the electrolyzer were periodically varied to determine its overall efficiency under various load conditions. Thanks to the island operation measuring devices, not only the overall power requirements but also the bipolar electrolyzer itself, the whole electrolyzer and the whole system with the analyzer were monitored. The hydrogen produced was further stored in metal hydride containers.

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Automatic x ray image characterisation for non destructive evaluation

Automatic x ray image characterisation for non destructive evaluation

Non-destructive testing (NDT) and non-destructive evaluation (NDE) techniques have a wide range of applications in industries via multiple methods, including Visual [1], Radiography [2], Ultrasonic [3], Eddy current [4], Acoustic emission [5] and Infrared thermography [6]. Non-destructive radiographic methods of inspection have been widely used to evaluate the integrity of material and equipment. Digital technology has been used for radiography data acquisition, radiographic image processing, defect detection and identification. Automatic defect characterisation for radiographic images is quite important especially in welded joints. These weld defects are commonly caused by porosity, slag inclusion, crack, undercut, burn through, lack of fusion, etc. [7]. However, the conventional method for non-destructive testing and evaluation is to judge the defects manually, which is not only subjective and time-consuming but also requires experienced personnel. This means that there is great demand for an automatic X-ray weld defect inspection system as shown in Fig 1.
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Pulsed Eddy Current Non-destructive Testing and Evaluation: A Review

Pulsed Eddy Current Non-destructive Testing and Evaluation: A Review

Less common probe configurations have also been used, such as a planar matrix probe that can generate a color map that is useful in the identification of defects [16]. Their work shows the use of an 8-by-8 array of sensors, as shown in Fig. 7(a), successfully maps the surface defects that have been artificially made on the sample, which justifies the complexity of the excitation and sensing circuits used in the probe. The application of independent excitations lead to a more uniform excitation field which, in turn, leads to a simpler interpretation of the detected signals. Another interesting example of the use of sensor array in ECT, is shown in Fig. 7(b), where the printed array is flexible and can be used to produce a color map of surface corrosion [16]. Another unique example is a symmetric excitation coil introduced by Yang et al, which is expected to gen- erate linear eddy currents with the benefit of virtually no field will be detected by the pick-up sensor when no defect is present [18].
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Noise reduction in ultrasonic Non-Destructive Evaluation (NDE) and imaging

Noise reduction in ultrasonic Non-Destructive Evaluation (NDE) and imaging

A wide variety of techniques have been investigated to suppress grain noise and enhance flaw detection through exploiting the key differences between defect echoes and grain noise. Since the defect (or a legitimate reflector) and grain boundaries often have different sizes, their scattering properties and responses have different spectral characteristics [3]. These differences have motivated temporal-spectral processing techniques given that the excitation signals are usually broadband, such as Weiner filtering [4, 5], split-spectrum processing [6-8], fragment recognition classifier [9], sub- spectrum phase coherence factoring [10], spectral distribution similarity analysis [11], and matched filtering [12, 13]. The defect echo typically has a coherent structure with energy mainly scattered from a single spatial point, while grain noise are spatially distributed throughout the insonified resolution cell. These differences have motivated spatial diversity and processing techniques, such as spatial beamforming [2, 14], coherence factoring [15], and spatially averaged sub-array correlation imaging [16, 17]. This chapter focuses on advanced matched filtering and spatial beamforming techniques for noise reduction in ultrasonic NDE. The signal matching concept has been extensively used in the detection of signals of known form in stationary noise in applications like radar and sonar [18], and more recently in the field of ultrasonic NDE [19, 20]. If the signal waveform and noise statistics are exactly known a priori, the matched filter is optimal in terms of the signal-to-noise ratio (SNR) improvement; this is unfortunately not the case in NDE. In this chapter, the matched filter design is investigated and extended into the scenario of inspection of coarse-grained materials. The filter is tuned to match the unknown defect echoes (rather than the transmitted signal) which are approximated by the superposition of multiple transmitted signals with different phase shift, time delay and amplitude gain that simulate reflections from an unknown spatially extended defect. An optimization paradigm is employed to search for the optimal parameters in the filter response in order to maximize the SNR gain over a set of training signals.
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NON DESTRUCTIVE METHOD FOR GENE AND DRUG DELIVERY IN LIVING CELL

NON DESTRUCTIVE METHOD FOR GENE AND DRUG DELIVERY IN LIVING CELL

 Electroporation itself works as an adjuvant to enhance the necessary "danger signals" that become detectable by the immune system. Electroporation can significantly enhance the potency of DNA vaccines: Pre-clinical testing in large animal models has shown that Inovio's electroporation-based DNA delivery technology increased neutralizing antibody production more than 100 times. Pre-clinical testing in large animal models has shown that Inovio's delivery technology increased the breadth and magnitude of T-cell production from a multi-antigen DNA vaccine against HIV. The test resulted in an increase in potency of the DNA vaccine by over 200 times. 32
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Capacitive imaging technique for non destructive evaluation (NDE)

Capacitive imaging technique for non destructive evaluation (NDE)

In this chapter, the use of FE models for the modelling of the fields from CI probes was discussed. Firstly, 2D models were constructed to demonstrate the electric field from the CI probe interacting with both non-conducting specimen and conducting specimen with an insulation layer. It has been demonstrated that the electric field distributions under the CI probe were significantly perturbed by the defects. 2D non- dimensional models were then used to study the effects of specimen thickness, lift-off distance and different electrical properties of the specimen. Those non-design related parameters are difficult to be studied experimentally. It has been revealed that such parameters can affect the measured signal in a complex way and need to be taken into consideration in practical measurements. The 2D models were also used to predict the probe response for three typical flaws, namely step, narrow groove and wide groove, on both insulating and conducting specimens. The results indicated that the presence of the insulating specimens can enhance the output while the conducting specimens deplete the output. In addition, it can be seen from the calculated CI probe responses, the edges of the defects on the conducting specimens were better defined compared to the insulating specimens.
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Advanced and Improved Non Destructive Method for Rail Axle Inspection

Advanced and Improved Non Destructive Method for Rail Axle Inspection

Abstract: The increasing use of high-speed trains, resulting in higher stress to the material and serious accidents with human injuries in the past, lead to a demand for shorter inspection intervals, extended scope of inspection and more stringent test requirements to be applied to the critical components. One component, which is inspected in regular intervals, is the axle of the railway wheel set. The manual ultrasonic inspection of used axles by experienced personal is time consuming (since several sound beam angles have to be used to cover the complete test area), expensive, and of course, subjective.
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Magnetic imaging system for display of local variations of magnetic properties in magnetic material

Magnetic imaging system for display of local variations of magnetic properties in magnetic material

A multiparameter magnetic imaging system and method to be used in the localized measurement of the magnetic properties of a material and the display of those properties in the form of a false color image indicating the occurrence of those properties across the surface of a sample specimen. The system includes an inspection probe to measure certain magnetic parameters across the surface of the specimen and means to determine a multiplicity of magnetic property values based on the measured data. The system also includes a visual display system which selectively displays the data relating to the determined magnetic properties in the form of a false color image indicating the presence and variation of these magnetic properties across the specimen surface.
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Non-destructive investigation of thermal diffusivity in a layered material using finite difference modeling

Non-destructive investigation of thermal diffusivity in a layered material using finite difference modeling

This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder (original author), cannot be used for any commercial purposes, and may not be altered. Any other use would require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or thesis from this database. For additional inquiries, please contact the repository administrator via email
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Sub Surface Flaw Detection of GFRP Components Using Non Destructive Methods

Sub Surface Flaw Detection of GFRP Components Using Non Destructive Methods

Non-destructive testing is an effective methodology to establish the characteristics of the material like internal flaws, surface discontinuities, porosity, de-bond and wall thinning, without affecting the quality and serviceability of the material [1]. It can also be described as a qualification or inspection process to determine the suitability of the material for the intended functioning with reference to some standards. Composite materials are the combination of two or base materials in macroscopic level in order to combine the advantages of the base materials. It has numerous advantages like high strength to weight ratio, increased stiffness, high fatigue strength to bring them as an essential material for various industries especially in aerospace [2].
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Investigation on packaging material of counterfeit Panadol variants and Creobic cream by non-destructive tests

Investigation on packaging material of counterfeit Panadol variants and Creobic cream by non-destructive tests

Although the better way to ensure a fake drug is by direct analysis of the active pharmaceutical ingredient (API), but this is not feasible due to short course therapies and what only remains is the packaging material. Nevertheless, most patients/customers will discard the packaging materials as thought to be unimportant although it contain most of the information pertaining to the medication.

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Magnetic field as a method of improving the quality of sowing material: a review

Magnetic field as a method of improving the quality of sowing material: a review

The cited research results cannot provide an unambigu- ous explanation of the mechanism of magnetic field effect on living organisms, in this case plant seeds. However, we can suppose that alternating magnetic field stimulates enzymatic activity, which causes an increase in seed germi- nation speed. Stimulated seeds not only germinate faster, but also more uniformly, they start vegetation as plants ear- lier, and thanks to this higher yields are obtained. At this point we can refer to the remarks of Wadas (1991) who states that magnetic field, below a certain limit value of in- tensity which is hard to define for various organisms, cau- ses an increase of enzyme activity, accelerating their me- tabolism. Increased enzyme activity under the effect of mag- netic fields is observed also in the organisms of animals. It is assumed, therefore, that this can be considered as a gene- ral rule of nature. It should also be emphasised that in the ef- fect of magnetic field on living organisms there is an absen- ce of any selectivity of that field. Magnetic field acts on all molecules, and thus also on those that do not require its effect. Weiss and Zerrenthin (1987) noted that although the effect of magnetic fields on living organisms (humans, animals, plants) fascinated researchers for a long time, magneto- biophysics as a science is still at its beginnings. He believes that in the nearest future magnetic fields will be applied on a large scale in biology, medicine, agriculture and in the economics of food materials.
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Comparision between Destructive and Non Destructive Test on Concrete

Comparision between Destructive and Non Destructive Test on Concrete

combination of aggregates (fine/coarse), cement and admixture if any. By suitably adjusting the proportion of various ingredients, concrete with sufficient compressive strength can be developed. Constructed structures have to be investigated for evaluating the serviceability and safety from time to time. The most important property of concrete is its strength which can be determined by destructive and non-destructive testing. It is important to have regular schedule for testing concrete structure, in order to have a safe and efficient operation of these structures. This schedule may vary depending on the structure use. DT is a method of testing to determine specimen’s failure. The main objective of performing destructive testing is to determine the service life of the specimen and to detect weakness of design that might not be shown under normal working conditions. NDT comprises of testing methods that are used to analyse the concrete specimen or structure without damaging or destroying it which is generally performed to investigate the material integrity of the specimen. NDT test are used worldwide to detect variation in structures, infinitesimal changes in surface finish and location of cracks or other physical discontinuities. There are various destructive and non- destructive test that can be employed for concrete. They are as follows:
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