Search results for "Inspec"
showing 10 items of 171 documents
Detection, characterization and sizing of hydrogen induced cracking in pressure vessels using phased array ultrasonic data processing
2016
Abstract Pressure vessels operating in sour service conditions in refinery environments can be subject to the risk of H₂S cracking resulting from the hydrogen entering into the material. This risk, which is related to the specific working conditions and to the quality of the steel used, shall be properly managed in order to maintain the highest safety at a cost-effective level. Nowadays the typical management strategy is based on a risk based inspection (RBI) evaluation to define the inspection plan used in conjunction with a fitness for service (FFS) approach in defining if the vessel, although presenting dangerous defects such as cracks, can still be considered “fit for purpose” for a giv…
Ultrasonic Guided Waves-Based Monitoring of Rail Head: Laboratory and Field Tests
2010
Recent train accidents have reaffirmed the need for developing a rail defect detection system more effective than that currently used. One of the most promising techniques in rail inspection is the use of ultrasonic guided waves and noncontact probes. A rail inspection prototype based on these concepts and devoted to the automatic damage detection of defects in rail head is the focus of this paper. The prototype includes an algorithm based on wavelet transform and outlier analysis. The discrete wavelet transform is utilized to denoise ultrasonic signals and to generate a set of relevant damage sensitive data. These data are combined into a damage index vector fed to an unsupervised learning…
Digital signal processing for rail monitoring by means of ultrasonic guided waves
2007
Recent train accidents have reaffirmed the need for developing rail defect detection systems that are more effective than those used today. One of the recent developments in rail inspection is the use of ultrasonic guided waves (UGWs) and non-contact probing techniques to target transverse-type defects. Besides the obvious advantages of non-contact probing, that include robustness and a potential for large inspection speed, such a system can theoretically detect transverse defects under horizontal shelling or head checks. This paper demonstrates the effectiveness of digital signal processing to enhance the damage detection sensitivity of the non-contact system. The method proposed here comb…
Les inspections primaires de l'éducation nationale : dotations, pratiques et effets sur le fonctionnement des écoles et les acquis des élèves
1997
This article analyses first the variety in the characteristics of local school inspectorates both in the quantitative (number of teachers) and in the qualitative (social background and geographic dispersion) dimensions. In relation to these, the article examines tne level of endowment (staffing and material) of the inpectorates and concludes to the lack of relationship between the resources mobilized and the needs at the local level. Then the practises of the inspectors and of their teams are described and here again a wide variety does exist across the different inspectorates in the administrative, relational and pedagogical dimensions of their activity (this variety in practices shows no …
Les rapports d'inspection du 1er degré, contenus et finalités : un exemple à La Réunion
2000
Azzedine Si Moussa - The primary education inspection reports, contents and objectives : an exemple in La Reunion. From a sample of primary education inspection reports of the Reunion academy, we aim to show how these reports could reflect the accuracy of pedagogical activities and the needs in teacher training. The logistic procedures also highlight that, for example, the probability for obtaining a bad remark about the application of a differential pedagogical approach is more significant among male teachers, at the CP level and in particular districts. The results provide some questions about the issues and the relevance of the current way of making inspection.
L'évaluation des enseignants : contexte, analyse et perspectives d'évolution
2012
Dans un contexte où l'évaluation des enseignants fait débat en France et où elle est susceptible d'évoluer vers de nouvelles modalités, ce texte propose d'analyser cette question en la situant dans une perspective globale qui associe les enjeux présents de la politique éducative aux apports de la recherche en éducation. On rappellera dans un premier temps certains apports de l'évaluation des systèmes éducatifs avant de mettre en évidence le rôle de l'enseignant comme déterminant essentiel des apprentissages des élèves. Nous nous centrerons dans un second temps sur les modalités actuelles de l'évaluation des enseignants dans notre pays et sur ses perspectives d'évolution en en dégageant les …
Conformable eddy current array delivery
2016
The external surface of stainless steel containers used for the interim storage of nuclear material may be subject to Atmospherically Induced Stress Corrosion Cracking (AISCC). The inspection of such containers poses a significant challenge due to the large quantities involved; therefore, automating the inspection process is of considerable interest. This paper reports upon a proof-of-concept project concerning the automated NDT of a set of test containers containing artificially generated AISCCs. An Eddy current array probe with a conformable padded surface from Eddyfi was used as the NDT sensor and end effector on a KUKA KR5 arc HW robot. A kinematically valid cylindrical raster scan path…
Gabor filters in industrial inspection: a review. Application to semiconductor industry
2005
This paper focuses on reviewing some recent works of the use of Gabor filters dealing with industrial applications. After a brief recall of Gabor filter basis, the two usual uses of Gabor filters are recalled: filter bank approach and filter design approach. The third part presents recent published works domain by domain. A fourth part exposes our own work with Gabor Filters for defect detection on semiconductor. A short conclusion summarizes the paper.
A novel visual pipework inspection system
2017
The interior visual inspection of pipelines in the nuclear industry is a safety critical activity conducted during outages to ensure the continued safe and reliable operation of plant. Typically, the video output by a manually deployed probe is viewed by an operator looking to identify and localize surface defects such as corrosion, erosion and pitting. However, it is very challenging to estimate the nature and extent of defects by viewing a large structure through a relatively small field of view. This work describes a new visual inspection system employing photogrammetry using a fisheye camera and a structured light system to map the internal geometry of pipelines by generating a photorea…
Guided Wave Propagation in a Plate Edge and Application to NDI of Rail Base
2012
The analysis of guided wave propagation in a plate edge can be useful for some applications, such as for the inspection of the rail base. Here guided waves generated by a laser beam hitting, on the inclined surface, a solid media with trapezoidal cross-section have been studied. We have found that, for the geometry investigated, two guided waves propagate along both free surfaces of the plate, with same velocity and frequency. The analysis of the trajectories of the two material points, due to waves propagation, shows that the wave packets can be identified as Rayleigh waves. The presence of S0 Lamb mode, with low frequency and low amplitude, has been revealed too. As an example of a possib…