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[en] The Probability of Detection (PoD) is a very useful aspect of an inspection. It is a measure of an inspection system and/or personnel's detection capabilities. The PoD can be used to quantify improvements to an inspection, as well as personnel performance changes. Although the PoD can be a useful NDT tool, it is not used extensively. This is mainly due to the complex mathematics behind the model. Evaluating a PoD has specific NDT requirements, as well as statistical requirements. (author)
[en] Punta Begoña Galleries, built in 1918 and located in the municipality of Getxo (Bizkaia, Spain) have a remarkable glazed ceramic decoration, whose current state of conservation presents an advanced level of deterioration. The study of the historical cultural property is framed within a multidisciplinary project, which aims to restore, recover and improve its historical and artistic value. In this sense, the recovery of the ceramic tiles is one of the crucial points, since it involves one of the visually most notorious elements. On the surface of the tiles, different degradations were observed, being the yellowish patina, one of the most significant. In order to carry out a cleaning treatment, the nature of the patina was evaluated, whose coating is a consequence of atmospheric contamination, as the chemical analyzes showed. Furthermore, a comparison was performed among four reactants both applied in reproduced pieces and in situ. To evaluate the effectiveness of the products, a quantitative evaluation was applied by colorimetry. In addition, this work shows an interdisciplinary methodology based on the scientific method as the best guide to achieve durable, safe and effective restoration methods.
[es]Las Galerías Punta Begoña, construidas en 1918 y ubicadas en el municipio de Getxo (Bizkaia, España) poseen una destacable decoración de cerámica vidriada, cuyo actual estado de conservación presenta un avanzado nivel de deterioro. El estudio del inmueble histórico cultural está enmarcado dentro de un proyecto multidisciplinario, que tiene como fin restaurar, recuperar y mejorar su valor histórico y artístico. En este sentido, la recuperación de la cerámica es uno de los puntos más cruciales, ya que supone uno de los elementos visualmente más notorios. En la superficie de los azulejos, se observaron diferentes degradaciones, siendo la pátina amarillenta, una de las más significativas. Con el fin de llevar a cabo una limpieza de la misma, se evaluó la naturaleza de la pátina, cuya veladura es consecuencia de la contaminación atmosférica, como mostraron los análisis químicos. A continuación se llevo a cabo una comparación entre cuatro disolventes orgánicos, aplicados tanto en probeta como in situ. Para evaluar la efectividad de los reactivos, se realizó una valoración cuantitativa mediante colorimetría. Además, el presente trabajo muestra una metodología interdisciplinaria basada en el método científico como la mejor guía a seguir para lograr métodos de restauración duraderos, seguros y efectivos.
[en] All NDT inspections use models. The number and type of models will vary between inspections. A qualified inspection will use a PoD model to evaluate detection capabilities. All techniques have some degree of calibration. Some calibration processes generate curves that are simple models. Parameters are the building blocks of models. Models can be generated to understand what happens to the results of an inspection when parameters change. Not all parameter variation will cause a decrease in a system's detection capability. For example, an increase in an indication's length will likely increase the chance of detection. Each variable or parameter involved in an inspection has natural variations. These variations will affect an inspection with different degrees. Evaluating when a change is significant becomes an important aspect in developing sound inspection techniques. This article addresses several techniques used to determine significance in changes between measurements. (author)
[en] This paper discusses methods of nondestructive testing, the main method is method of acoustic flue gas emission. It was found that the use of this method in the diagnosis of bottom pipe and dug-in areas allows to reduce time, does not require surface dressing to a certain value, provides almost instant information about the defect at a great distance to the nearest gas-pumping station and is not inferior to the reliability of the control other existing methods. (paper)
[en] For standard reinforced concrete, there are several non-destructive test (NDT) methods available for measuring the concrete cover and for locating subsurface objects and defects. Whether or not these methods may also be applied to fibre reinforced concrete has been the subject of a recent study. The results and a recommendation for the most suitable technology for use with fibre reinforced concrete is the topic of this paper. (paper)
[en] Industrial electron accelerators have been introduced to Asian countries in 1960s, at first for polymer modification, and grown with the economic growth of Asia in 1990s and 2000s. Nowadays over 1,000 electron accelerators are used for industries in this region, and the demand is still growing. Electron accelerators are mainly used for surface treatment, cross-linking and modification of polymeric products those which are closely related with automobile industries. Also the need for sterilization of medical stuff and food pasteurization is growing as the improvement of the quality of life. Understanding the radiation chemical effect has allowed to harness the electron beam for a variety of applications, and the new approaches, such as conversion to X-ray for non-destructive testing, environmental pollution control have wide applicability to all sorts of different problems of human life. (author)
[en] Seven factors play a role in the quality of a weld: 1) the metals of the parts to be welded, 2) the materials brought by the welding process that will be incorporated in the weld, 3) the welding process itself, 4) welder's technical skills, 5) the welding equipment, 6) the technical referential, and 7) the regulatory referential. In nuclear industry, technical and regulatory requirements concern the first 5 factors. The aim is to reinforce the high quality of the welds and to be sure that they have been properly made following the rules of the RCC-M construction code. The RCC-M code foresees a gradation of requirements for the welds according to the safety standard of the equipment. 3 levels have been defined: N1, N2 and N3, N3 corresponding to the highest level that is applicable to the primary and secondary cooling circuits of reactors. (A.C.)
[en] One of the most important applications of gamma based NDA technique is the assay of low-density 200 L waste drums containing low/intermediate level of activity. Segmented gamma-ray scanning (SGS) is the most commonly employed technique for the assay of such heterogeneous samples. This technique accounts for the variation of matrix materials in different segments but assumes both the source and matrix to be homogeneously distributed in each segment. For situations where the radionuclide source distribution as well as matrix distribution is significantly heterogeneous, SGS technique may lead to large errors. Another advanced NDA technique to assay radioactive waste is tomographic gamma scanning (TGS). The TGS combines transmission and emission reconstructive tomography techniques in an effort to improve the accuracy of the measurement, when the radionuclide is distributed non-uniformly in a heterogeneous matrix. With this aim, an integrated segmented and tomographic gamma scanning system (ISTGS) has been designed and fabricated for the assay of alpha active waste in 200 L drum. The system can operate in both modes, SGS mode for measuring nearly homogeneous waste and in TGS mode, for measuring heterogeneous waste. It consists of a sample platform capable of translating and rotating drum. The system also consists of a highly collimated 152Eu source (7 mCi) with motorized shutter for the transmission scan, named as the transmission source assembly. Another motorized collimator system is placed in front of the detector with a length of ~44 cm and variable aperture, thereby making the system capable of being used for low as well as high count rate samples. All the collimators have been made of high purity lead (97%)
[en] A fairly new method of manufacturing components - additive manufacturing could send shock waves through the manufacturing industry in the near future. Additive manufacturing is a process where objects are built by adding layer -upon-layer of material, whether the material is plastic, metal, concrete, or other materials. This is different from current manufacturing (subtractive manufacturing), as an object is typically made as a blank form and subsequently reshaped in the manufacturing processes such as machining, forging, etc. The process behind additive manufacturing is fairly simple: 3-D modeling software is used to create a blueprint. That blueprint is then used to create a component using different methods and materials. The object is then created layer-by-layer until completed.