616,701 research outputs found

    Development of thermoelastic stress analysis as a non-destructive evaluation tool

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    A modified methodology is proposed in which only a single transient load is used for the TSA measurement. Specimens with different damage severities are tested and it is shown that the modified TSA method has the potential to be applied in the field as a non-destructive evaluation tool

    COST Action G8 : Non-destructive Analysis and Testing of Museum Objects

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    COST Action G8 (2000-2004) aims at creating a Europe- wide network that would enable co-operation and interaction between two groups of professionals: people directly concerned with the maintenance of our cultural heritage – conservators, curators, art historians, archaeologists – and analytical scientists, including chemists, physicists, geologists, metallurgists, mineralogists and microbiologists. The main objective of the action is to improve preservation and conservation of our cultural heritage by increasing knowledge of museum objects through non-destructive analysis and testing. The scientific activities of COST G8 include organising short-term scientific missions to train scientists of both groups in the other's field as well as to transfer practical experience among the European countries. Regular meetings in the form of workshops are organised in order to exchange the obtained knowledge in a broader group, and six working groups are active, which allows close collaboration in a specific field

    Acoustic emission analysis as a non-destructive test procedure for fiber compound structures

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    The concept of acoustic emission analysis is explained in scientific terms. The detection of acoustic events, their localization, damage discrimination, and event summation curves are discussed. A block diagram of the concept of damage-free testing of fiber-reinforced synthetic materials is depicted. Prospects for application of the concept are assessed

    Looking beneath Dalí's paint: non-destructive canvas analysis

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    A new analytical method was developed to non-destructively determine pH and degree of polymerisation (DP) of cellulose in fibres in 19th 20th century painting canvases, and to identify the fibre type: cotton, linen, hemp, ramie or jute. The method is based on NIR spectroscopy and multivariate data analysis, while for calibration and validation a reference collection of 199 historical canvas samples was used. The reference collection was analysed destructively using microscopy and chemical analytical methods. Partial least squares regression was used to build quantitative methods to determine pH and DP, and linear discriminant analysis was used to determine the fibre type. To interpret the obtained chemical information, an expert assessment panel developed a categorisation system to discriminate between canvases that may not be fit to withstand excessive mechanical stress, e.g. transportation. The limiting DP for this category was found to be 600. With the new method and categorisation system, canvases of 12 Dalí paintings from the Fundació Gala-Salvador Dalí (Figueres, Spain) were non-destructively analysed for pH, DP and fibre type, and their fitness determined, which informs conservation recommendations. The study demonstrates that collection-wide canvas condition surveys can be performed efficiently and non-destructively, which could significantly improve collection management

    Non destructive identification of wolly peache using impact response near infrared spectroscopy

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    A procedure which combines impact response and near-infrared sensing in a two-step classification method has been developed for identification of woolly peaches. Two hundred and seventy Maycrest peaches from three ripeness stages at harvest, stored during 0, 1, 2, 3 and 4 weeks at 1 and 5°C, were tested by non-destructive techniques (non-destructive impact and near-infrared spectroscopy) in order to assess woolliness (also known as mealiness in apples). Destructive mechanical tests (Magness–Taylor, confined compression and shear rupture) were used as a reference method to identify woolly fruits. Non-destructive impact data were processed by discriminant analysis to segregate into two texture categories (crispy–firm–hard and non-crispy–non-firm–soft). In the same way, discriminant analysis techniques were used to classify into three juicy categories (low juicy, medium juicy and high juicy), according to the near-infrared second derivative curve. Combining non-destructive impact and near-infrared spectroscopy, not crispy, not firm and soft fruit from the low juicy group were classified as woolly. The percentage of correctly classified fruits in both categories was 80%. The conditions about the experimental factors which enhance woolliness obtained from the destructive procedures were confirmed by the non-destructive procedure
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