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Vaithiyanathan V.,SASTRA University | Anishin Raj M.M.,SASTRA University | Venkataraman B.,Radiological Safety and Environmental Group
European Journal of Scientific Research | Year: 2011

Non destructive testing (NDT) is the technique of identifying the properties of material without making any damage. Due to errors in welding, weld defect arises, the process of identifying or detecting the weld defect is an important application in the field of Non-Destructive Testing (NDT).Analysis and comparison of various segmentation methods for weld defects identification such as Lack of Penetration, Porosity and Oxide Inclusion is presented in this paper with experimental results. Identifying weld defects using human eye is almost impossible, since the radio-graphic images will be very dark and low in contrast. Image segmentation is the process of identifying objects from the images using mathematical concepts which is a time consuming and tough task. Defects or discontinuation in welding occurs due to various reasons such as gas entrapment, lack of penetration, too much heat, oxide inclusion, etc. This paper, we performed Watershed, Hough Transform and Region Growing segmentation. The results are compared and conclusions are achieved. © EuroJournals Publishing, Inc. 2011.

Vaithiyanathan V.,SASTRA University | Venkataraman B.,Radiological Safety and Environmental Group | Anishin Raj M.M.,SASTRA University
Journal of Theoretical and Applied Information Technology | Year: 2011

X-ray radiography is commonly used in (NDT) Non-destructive Testing, for identifying defects in weld. When the X-ray is passed through the weld object, the area where the defects are occurred will be having different intensity profile, than the nearby pixels. Most of the X-ray radiographic images will be having some forms of noise components embedded in it. Median filter is applied for noise removal, followed by gamma correction for image enhancement which made the image more operative. For the segmentation of the weld defect, watershed method is performed. Through watershed segmentation process, the defective regions are segmented out, without oversegmentation problem. Standard derivation and mean of the Projection Profile of the radiographic image along with RST invariants features are used for feature extraction. In this work, we fed the feature extracted to a Learning Vector Quantization (LVQ) for training, with four different output classes, where each class corresponds to different classes or types of weld defects like Cluster Porosity, Slag inclusions, Lack of Penetration (LOP) and Burn-Through. The result shows that the proposed system is highly efficient in classifying different types of weld defects. © 2005 - 2011 JATIT & LLS. All rights reserved.

Ilaiyaraja P.,Radiological Safety and Environmental Group | Kumar Singha Deb A.,Bhabha Atomic Research Center | Ponraju D.,Indira Gandhi Center for Atomic Research | Venkatraman B.,Radiological Safety and Environmental Group
Journal of Environmental Chemical Engineering | Year: 2015

Xanthate functionalized PAMAM dendrimer (XFPD) chelating ligand, first of its kind, has been synthesized from hydroxyl terminated poly(amido)amine dendrimer. Studies on performance of XFPD in removal of Cu2+ and Eu3+ metal ions were carried out from aqueous solution. Investigation on quantitative removal of Cu2+ and Eu3+ metal ions at various pH revealed that XFPD effectively precipitates the metal ions at pH > 4 with settling time of about 3 h. In case of Cu-XFPD complex at pH > 6, settling requires the addition of coagulating agent like aluminium sulphate. The loading capacity of XFPD for Cu2+ and Eu3+ metal ions was estimated to be 0.48 and 0.95 g g-1, respectively. The XFPD chelating ligand deployed for treatment of radioactive liquid waste (RLW) showed that percentage removal of radionuclides were in the following order; 95Zr ≈ 154Eu ≈ 60Co (>99.8) > 144Ce (98.8) > 125Sb (83.3) > 106Ru (79.4) > 55Mn (54.3) > 137Cs (24.0). It has been demonstrated that XFPD chelating ligand has potential application in effective removal of various radionuclides from aqueous waste. © 2015 Elsevier Ltd. All rights reserved.

Rajeev C.B.,Radiological Safety and Environmental Group | Kuppusamy M.V.,Radiological Safety and Environmental Group | Ramesh G.,Radiological Safety and Environmental Group | Dhananjeyakumar M.,Indira Gandhi Center for Atomic Research | And 2 more authors.
Procedia Engineering | Year: 2014

Nuclear fuel cycle facility under construction at Kalpakkam houses more than 200 process vessels and equipments of different capacity and configurations and about 62 Kms of piping of varying sizes from 8 DN to 250 DN in about 5000 m3 of concrete cell volume. Austenitic stainless steel 304L has been widely used as work horse material for this plant due to its resistance to corrosion in acidic environment. The fabrication works of this facility involves more than 70000 weld joints for interconnecting various vessels, equipment and associated piping system. Pneumatic pressure testing and soap bubble leak testing are the two methods effectively used to assess the final integrity of the system after fabrication and erection. Physical verification of entire piping system as per the approved as-built drawing is a pre pneumatic test requirement. During physical verification, entire piping system will be physically scanned by visual inspection methods for orientation, gradient and also to identify any surface imperfections. Even though all surfaces of the piping system are examined before giving clearance for welding, the surfaces will be re-examined prior to integrity testing to ensure that piping system orientation is as per approved design and its surfaces are free from damages. Orientation and slope plays an important role in nuclear fuel cycle facility. Because nuclear fuel cycle facility is designed in such a way that gravitational force is effectively used to transfer process fluid to avoid the usage of moving mechanical parts. This is one of the zero maintenance design feature of nuclear fuel cycle facility. Based on experience many procedures are developed to ensure the intended design requirements. Before proceeding to the integrity testing, one has to verify the completion of all quality control stage inspection activities during fabrication by way of documents verification pertaining to the weld joints and loop involved in the testing. All inspection documents right from raw material identification, fabrication and inspection of components are to be verified prior to integrity testing. Verification of large number of inspection related documents posses a very big challenge. To meet this herculean task in time, an asset management system is designed and developed in house. Asset management system plays a key role in storage and retrieval of all inspection credentials and NDE images involved in the system, and with least amount of time these can be retrieved and verified. The asset management system also plays a constructive role during the pre commissioning activities of the plant. This paper emphasis the optimization methodologies adopted during integrity testing. © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.

Sudheera K.,Sathyabama University | Nandhitha N.M.,Sathyabama University | Nanekar P.,Bhabha Atomic Research Center | Venkatraman B.,Radiological Safety and Environmental Group | Rani B.S.,Sathyabama University
Proceedings of the 2013 International Conference on Advanced Electronic Systems, ICAES 2013 | Year: 2013

Ultrasonic Testing is a highly reliable Non-Destructive Testing Technique for weld defect characterization. Defects occur either high frequency components (Porosity, Sidewall crack) or as low frequency components (Root, Lack of Fusion, Lack of penetration, slag) in the UT signal. Manual interpretation of these signals is subjective in nature and is dependent on the expertise of the individual. Hence it is necessary to develop automated signal analysis system that classifies the defect. As defect classification is non-linear in nature, neural network based classification techniques are cited in literature. However neural network based techniques are computationally complex and has prediction error. Hence in this paper, an effective range based classification system using statistical moments is proposed. Performance of the proposed technique is measured in terms sensitivity and specificity. ©2013 IEEE.

Ilaiyaraja P.,Radiological Safety and Environmental Group | Singha Deb A.K.,Radiological Safety and Environmental Group | Ponraju D.,Indira Gandhi Center for Atomic Research | Venkatraman B.,Radiological Safety and Environmental Group
Desalination and Water Treatment | Year: 2014

Removal of cobalt from aqueous solution by indigenously synthesized xanthate functionalized dendrimer (XFD) was xinvestigated. Effect of pH and interference due to complexing agents/other cations on removal of cobalt by precipitation method was studied. Loading capacity of XFD as a function of cobalt concentration was estimated; about 0.355 g of cobalt could be loaded per gram of XFD at pH 4.5. It was observed that quantitative precipitation is effective at pH > 3 and the suspended particles are not settling down when the pH of feed solution is more than 6. The suspended particles settle down by the addition of coagulating agent (aluminum sulfate). The presence of Sr2+ or Mg2+ cations enhances precipitation process whereas monovalent Na+ ion has no significant effect on cobalt removal by XFD ligand. Toxicity characteristics leaching procedure and semi-dynamic leaching test results show that Co-XFD complex is a characteristic leaching toxic and needs further treatment before dumping into the sanitary landfills. © 2013 © 2013 Balaban Desalination Publications. All rights reserved.

Sudheera K.,Sathyabama University | Nandhitha N.M.,Sathyabama University | Ganesh N.V.S.L.,Sathyabama University | Nanekar P.,Bhabha Atomic Research Center | And 2 more authors.
International Conference on Communication and Signal Processing, ICCSP 2014 - Proceedings | Year: 2014

Ultrasonic Testing is the widely used NDT technique for flaw detection in thick walled weldments. It is an indirect technique and the signals are to be analyzed in order to characterize the flaw. Manual interpretation of these signals is subjective in nature and is dependent on the expertise of the individual. Hence the paradigm has shifted to automated signal analysis. In this paper a successful attempt has been made to develop a pattern among the flaws of same type without using Artificial Neural Networks. Here, the signals are analyzed with Stockwell transform and the pattern is determined. Also quantitative characterization is done with mean, standard deviation, root mean square value, peak to rms ratio. © 2014 IEEE.

Sudheera K.,Sathyabama University | Nandhitha N.M.,Sathyabama University | Mohanachandran L.,Sathyabama University | Nanekar P.,Bhabha Atomic Research Center | And 2 more authors.
Advanced Materials Research | Year: 2014

Industrial Radiography is the most widely accepted NDT technique for weld quality in industries. As it is an indirect method, defect type and nature must be obtained by analyzing the radiographs. Manual interpretation of radiographs is subjective in nature. So the paradigm shifted to automated weld defect detection system. Though considerable research is done in automated weld defect detection, an accurate domain specific technique has not yet been evolved due to noise, artifacts in radiographs, low contrast between the defect region and the background and difficulty in isolating the defect. The proposed work aims at developing an automated weld defect detection system that enhances the contrast between the object and the background and isolates the weld defect. In this work, real time weld radiographs are acquired and contrast enhancement is performed with DWT. Slag and Porosity are isolated and dimensionally characterized. © (2014) Trans Tech Publications, Switzerland.

Anishin Raj M.M.,SASTRA University | Venkataraman B.,Radiological Safety and Environmental Group | Vaithiyanathan V.,SASTRA University
European Journal of Scientific Research | Year: 2012

This paper presents comparative study and experimentation of simultaneous Reconstruction Technique (SART) and Ordered Subsets Expectation Maximization (OSEM). The SART and OSEM methods are used to reconstruct the object from the X-ray projection obtained on the detector. The process of creating back the object image from the Radon Transform of the object is known as Image Reconstruction. Image reconstruction is a famous and interesting field which comes under computed tomography. Computed Tomography is used in NDT for identifying the hidden or inner defects of objects by reconstructing the image through Filtered back projection or iterative reconstruction technique. In this paper Simultaneous Algebraic Reconstruction technique and Ordered Subsets Expectation Maximization methods are implemented and the experimented results are compared using performance parameters for various test cases and conclusion is achieved. © EuroJournals Publishing, Inc. 2012.

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