TY - JOUR A1 - Westwood, S. A1 - Josephs, R. D. A1 - Choteau, T. A1 - Martos, G. A1 - Wielgosz, R. A1 - Sarzuri, Y. A. A1 - Mendoza, E. A1 - do Rego, E. C. P. A1 - Violante, F. G. M. A1 - da Silva Souza, W. A1 - de Carvalho, L. J. A1 - Fernandes, J. L. N. A1 - Bates, J. A1 - Rajotte, I. A1 - Melanson, J. E. A1 - Li, H. A1 - Guo, Z. A1 - Su, F. A1 - Wang, S. A1 - Huang, T. A1 - Lalerle, B. A1 - Gantois, F. A1 - Piechotta, Christian A1 - Philipp, Rosemarie A1 - Kaminski, Katja A1 - Klyk-Seitz, Urzsula-Anna A1 - Giannikopoulou, P. A1 - Skotidaki, E. A1 - Kakoulides, E. A1 - Pui-Kwan, C. A1 - Kuroe, M. A1 - Itoh, N. A1 - Calderón, M. A. A. A1 - Contreras, L. R. A1 - Osuna, M. A. A1 - Alrashed, M. A1 - Ting, L. A1 - Mei, G. E. A1 - Juan, W. A1 - Sze, C. P. A1 - Lin, T. T. A1 - Quinn, L. A1 - Swiegelaar, C. A1 - Fernandes-Whaley, M. A1 - Ahn, S. A1 - Chaiphet, T. A1 - Sudsiri, N. A1 - Bellazreg, W. A1 - Bilsel, M. A1 - Colombo, G. T1 - Key comparison CCQM-K78.b - non-polar analytes in organic solvent: methoxychlor and trifluralin in acetonitrile N2 - The CCQM-K78.b key comparison was coordinated by the Bureau International des Poids et Mesures (BIPM) on behalf of the CCQM Organic Analysis Working Group (OAWG) of the 'Comité Consultatif pour la Quantité de Matière' (CCQM), for National Measurement Institutes (NMIs) and Designated Institutes (DIs) providing measurement services in organic analysis under the 'Comité International des Poids et Mesures' (CIPM) Mutual Recognition Arrangement (MRA). This key comparison was conducted as a 'Track A' comparison within the OAWG's 10-year strategic plan. The goal of CCQM-K78.b was to underpin capabilities for the value assignment of calibration solutions containing low polarity/non-polar organic analytes in organic solvents. The selected model system consisted of a two-component pesticide solution in acetonitrile, comprising methoxychlor and trifluralin. Participants were tasked with assigning the mass fractions, in units of μg/g, of methoxychlor and trifluralin in acetonitrile solution. The mass fraction levels and analytical challenges of the selected analytes were representative of those encountered for calibration solutions of non-polar organic analytes. Participation in CCQM-K78.b allowed for the benchmarking of capabilities for assigning the mass fraction of non-polar organic compounds (pKow < -2) in solution, at mass fractions above 5 μg/g, in an organic solvent. Additionally, the comparison assessed the capabilities for the quantitative assignment of thermally labile compounds. Participants were provided by the BIPM with ampoules containing methoxychlor and trifluralin in acetonitrile. Each participant reported the mass fraction content of each analyte in μg/g. All participants ensured the metrological traceability of their results through the use of a Primary Reference Material (PRM), which was used to prepare a primary calibrator solution for each analyte using a gravimetric procedure. The twenty participating institutes primarily used analysis procedures based on GC-MS, -IDMS, -MS/MS, -ECD, and -FID, with some participants also using LC-UV for the value assignment. The analysis of methoxychlor and trifluralin in acetonitrile solution presented several challenges, including the thermal stability of the analytes under selected analytical techniques, control of solvent volatility, and considerable variation in some results using MS-based quantification methods. The mass fraction assignments for methoxychlor and trifluralin, consistent with the key comparison reference values (KCRVs), were achieved with associated relative standard uncertainties of (0.38 - 2.9) % for methoxychlor and (0.35 - 2.5) % for trifluralin. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA). KW - Methoxychlor KW - Trifluralin KW - CCQM KW - Key comparison PY - 2025 DO - https://doi.org/10.1088/0026-1394/62/1A/08010 SN - 0026-1394 VL - 62 IS - 1A SP - 1 EP - 37 PB - IOP Publishing AN - OPUS4-64691 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pimentel, A. S. O. A1 - Guesser, W. L. A1 - Custódio da Silva, W. J. R. A1 - Portella, Pedro Dolabella A1 - Woydt, Mathias A1 - Burbank, J. T1 - Abrasive wear behavior of austempered ductile iron with niobium additions N2 - Carbidic Austempered Ductile Iron (CADI) microstructures containing eutectic carbides can be produced by the addition of carbide stabilizing elements, such as chromium. Carbides formed from the addition of Cr are eutectic of M3C type. The presence of such hard phases can enhance the abrasion wear resistance of ductile iron. A new CADI can be produced by the addition of Nb. Niobium carbide particles are formed in the beginning of solidification and remain stable once they are insoluble in solid iron matrix. The dry sand abrasive wear resistance of ductile irons alloyed with 1.0, 1.8, and 2.4 wt% Nb were tested in both “as-cast” and “heat treated” conditions using standard ASTM G65. Results were compared to abrasive wear data obtained on ductile iron alloyed with 1 wt% Cr, CADI (1 wt% Cr), and the basic composition of iron without carbide stabilizing elements. In the “ascast” condition, the addition of Nb did not lead to a reduction in wear, while CADI with Nb is a promising substitute for CADI with Cr addition, because both materials showed very similar values of abrasion resistance. Micro-ploughing and micro-cutting mechanisms were observed on the worn surfaces of ductile irons. Abrasive wear resistance of these alloys was correlated with the volume fraction of carbides. KW - arbidic austempered ductile iron KW - Ductile iron KW - Niobium alloying KW - Abrasion PY - 2019 DO - https://doi.org/10.1016/j.wear.2019.203065 VL - 2019 IS - 440–441 SP - 203065 PB - Elsevier CY - Amsterdam, Niederlande AN - OPUS4-50784 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silva, W. A1 - Zscherpel, Uwe A1 - Ewert, U. A1 - Lopes, R. T1 - Analysis of angular dependent spatial frequency response of Digital Coplanar Translational Laminography N2 - Digital Coplanar Translational Laminography (CTL) is a radiographic imaging technique that permits the visualization of structural details and discontinuities in the object of interest after 3D reconstruction from multiple projections. This technique becomes quite competitive regarding to computed tomography in situations of arrangements in which no complete rotation of the X-ray source - detector system around the object of interest is accessible or in cases where the part to be inspected has a high geometric asymmetry. The literature does not show many studies about image quality for different laminographic reconstructions and scan geometries. Different methodologies for measuring the Modulation Transfer Function (MTF) as a key image quality parameter for the aforementioned technique are applied. The MTF was measured using different approaches, presampled MTF or sampled MTF, both based on the Fourier Transform-Magnitude Spectrum or the square wave MTF using line pattern gauges. A sample known as Siemens Star with a converging line pattern was used to measure the circular square wave MTF. This circular MTF provides information on the direction dependent contrast transfer related to the measurement conditions, the reconstruction algorithms and the translational scan direction. For this purpose, several MTF measurements were performed in multiple angular directions. Beyond it, reconstructions were performed using different algorithms (Filtered Shifted Average) and an iterative one (MART – Multiplicative Algebraic Reconstruction Technique). Image quality analysis were done for both reconstruction methods. MART showed an image quality improvement for challenging conditions for laminographic arrangements, such as for a low number of projections (down to 25 for this study, considered as limited view, limited angle reconstruction). Additionally, a Gadolinium gauge with parallel line patterns within a range from 10 μm to 1000 μm was used to compare the square wave MTF with the sine MTFs, measured by the different techniques mentioned above. The results show that the MTF techniques presented are equivalent in this study. The results obtained for this Gadolinium plate showed a good agreement between MTF10% and SRb image measurements. The methodology presented here is used for the characterization of the frequency dependent spatial resolution of measurements obtained from different laminographic reconstruction techniques and scan geometries. Finally, from the acquisitions and reconstructions obtained with the Siemens Star, cross laminographic images were calculated in order to improve the direction dependent sensitivity. The results showed a better detectability for cross laminographic images in comparison to unidirectional coplanar translational laminographic images covering dead zones. KW - Laminography KW - Image quality KW - Modulation transfer function KW - Cross laminography KW - Reconstruction algorithms PY - 2021 DO - https://doi.org/10.1016/j.ndteint.2021.102546 SN - 0963-8695 VL - 124 SP - 1 EP - 13 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-53845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silva, W. A1 - Lopes, R. A1 - Zscherpel, Uwe A1 - Meinel, Dietmar A1 - Ewert, Uwe T1 - X-ray imaging techniques for inspection of composite pipelines N2 - The literature has shown that the application of laminography provides advantages as 3D radiographic imaging with depth information for in house and mobile testing. This permits to distinguish between overlapping indications, measure the extension along radiation direction and classify indications as surface open or subsurface ones as required in critical engineering assessment. This work provides a comparative study and measurements of the three techniques Digital Radiography (DR) with Digital Detector Arrays (DDA), Coplanar Translational Laminography (CTL) and Computed Tomography (CT), applied for composite pipeline inspection. It is demonstrated that CTL and CT provide advantages for the evaluation of pipe-to-pipe connections and the evaluation of adhesive applications. They show indications of discontinuities with higher contrast sensitivity than radiography. Beyond it, two specimen, namely Phantom 1 and Phantom 2, were developed and manufactured by additive manufacturing to analyze the preferential detection sensitivity and the direction of features and depth information for laminographic measurements. Another goal was to show the laminographic capabilities to distinguish between overlapping discontinuities. CTL is especially suitable for mobile inspection. Special glass fiber reinforced polymer samples (GRP) were manufactured for further analysis and comparisons between the abovementioned techniques. Finally, Phantoms 1 and 2 show the capability of laminography to detect overlapping indications and also show that discontinuities oriented perpendicular to the scan direction have the highest contrast sensitivity for laminographic measurements. KW - Digital Radiography KW - Laminography KW - Computed Tomography KW - Composite Pipes KW - Image Quality PY - 2021 DO - https://doi.org/10.1016/j.micron.2021.103033 SN - 0968-4328 VL - 145 SP - 103033 PB - Elsevier Ltd. AN - OPUS4-52415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -