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Die Empfindlichkeit von Eindring- und Magnetpulverprüfungen (PT, MT) hängt unter anderem von der Eignung und der Qualität der Prüfmittel ab (für PT bezeichnet als Eindringsystem). Die Ermittlung der Empfindlichkeit erfolgt an Kontrollkörpern mit natürlichen und künstlichen Inhomogenitäten durch Ermittlung der Anzeigenerkennbarkeit als Maß für die Eignung. Die europäischen Normen spezifizieren die Anforderungen an die Prüfmittel für Typen-, Chargen- und Betriebsprüfungen nach pr EN ISO 3452-2 für PT und EN ISO 9934-2 für MT. Dieser Beitrag beschreibt die Ermittlung der Empfindlichkeit von Prüfmitteln sowie deren Qualifizierung bei der Typenprüfung. Die vorgeschlagenen Verfahren wurden durch experimentelle Untersuchungen validiert, bei denen ein Bildverarbeitungssystem zur Ermittlung der Anzeigenerkennbarkeit verwendet wurde. Im Hinblick auf die Qualifizierung der Prüfmittel wird die Zuverlässigkeit der Verfahren diskutiert.
Apparently that the type testing procedure should be conducted under the conditions ensuring reproducibility of its outcomes. We investigated various factors effecting upon the reproducibility. To obtain quantitative characteristics of indications visibility the image-processing hard-and software were used. It was established that there are two main groups of these factors. The first depends on the differences between various test panels, which are used for type testing. The second one concerns the reproducibility of some stages of penetrant testing procedure (excess penetrant removing and developer application). The recommendations to increase the reproducibility of type testing are developed and illustrated experimentally.
The determination of penetrant system sensitivity as a part of type testing should be conducted ensuring reproducibility of the result. We investigated some factors effecting the reproducibility. To obtain quantitative characteristics of indications visibility, an image processing system was used [1]. We used 3 different sets of reference blocks (rb1, rb2, rb3) corresponding to type 1 of EN ISO 3452-3 [2]. Two fluorescent penetrants with different sensitivities and the same wet solvent developer were used.
It was established that the reproducibility of type testing is influenced by mainly two principal factors. First there are the differences between reference blocks. Second one concerns the reproducibility of penetrant testing procedure, especially excess penetrant removal and developer application.
According to EN ISO 3452-3 a reference block for determination of sensitivity level of fluorescent penetrants consists of a set of three nickel-chrome plated panels with 10, 20 and 30 µm plating thickness. Transverse cracks are made in each panel by stretching the panels in the longitudinal direction and width to depth ratio of the cracks should be approximately 1/20. Each panel presents a certain sensitivity level, which is characterised by the level of visibility of the indication. The highest level 3 corresponds to the panel with 10 µm thickness plating. Each panel is cut longitudinally (perpendicular to the crack) so that 2 sheets (panels A and B) with nearly the same cracks will be produced. These panels A and B of a reference block are used for relative evaluation, for example to compare sensitivities of two penetrants. It is considered that the application of the same penetrant to both panels with subsequent adequate development results in the same visibility of the indications on these panels.
Quantitative correlations between the abilities of the reference blocks used for determining of the sensitivity were obtained in our investigations. We used the relations between the measured values of light-fluxes from the indications of similar comparing areas on two panels. These indications correspond to certain cracks parts of the same total length on both comparing areas. The relations of the steps between the panel are responsible for the definition of the sensitivity groups. From our investigations it follows that the steps of the different sets are different. Besides it was established that the indications visibility for the same penetrant applied on different reference blocks might have a considerable difference depending on the penetrant sensitivity: the higher penetrant sensitivity, the smaller is such a difference between the steps 30/20 and 20/10. For example, for rb3 the relations 30/20 and 20/10 for lower sensitive penetrant (I1) reached factor 3 comparing with factor 2 for higher sensitive penetrant (I2).
Some results of the comparison between the 3 sets (rb1, rb2, rb3) investigations are summarised in Table 1 with rb1 as a reference.
This paper focuses on the preparation and characterization of crystalline thin films of rare-earth-doped sesquioxides (Y2O3, Lu2O3) grown by pulsed laser deposition on single-crystal (0001) sapphire substrates. X-ray diffraction measurements show that the films with thicknesses between 1 nm and 500 nm were highly textured along the 111 direction. Using Rutherford backscattering analysis, the correct stoichiometric composition of the films was established. The emission and excitation spectra of europium-doped films with a thickness 100 nm look similar to those of the corresponding crystalline bulk material, whereas films with a thickness 20 nm show a completely different emission behavior.
To date, in the textile manufacturing process of warp knitting, trouble-shooting and process optimization mainly rely on empirical knowledge and experiments. This factor limits the achievable increase in productivity and quality. On the other hand, using simulations, different phenomena that affect the quality of the knitted fabric and the knitting process can be clarified in the run-up of the experiments. Consequently, an increase in quality and flexibility can be reached with reduced experimental effort. This paper presents a process simulation of the warp thread dynamics in the thread feeding system of a warp knitting machine. For this purpose, a continuum model of the warp thread that includes the spatial dynamics of the thread and the axial transport movement has been developed.
Four hundred sixteen silver coins stemming from the Ottoman Empire (16th and 17th centuries) were analyzed in order to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. As most of the coins showed the typical green patina on their surfaces due to corrosion processes which have led to the depletion of copper in the near-surface domains of the silver coins in comparison to their core composition, small samples by cutting splinters from the coins had to be taken, embedded in synthetic resin and cross-sectioned in order to investigate the true-heart metal composition. The type of the alloy was investigated as well as if coins minted in different locations demonstrated homogeneous traits concerning the predominant impurities which could suggest a common ore. Several X-ray based techniques (µ-XRF, µ-SRXRF and µ-PIXE) could be applied in order to determine the silver contents as well as the minor and trace elements. Finally, SEM/EDX was applied in order to study the homogeneity/heterogeneity of the coins and the presence of surface enrichments. In general, the silver content of the analyzed specimen varies between 90% and 95%. These outcomes have not supported the historical interpretations, which predict that during the period studied a debasement of approximately 44% of the silver content of the coins should have occurred.
Validierte Messverfahren für die nichtgeometrische Größe Hydrophilie - Anwendung in der Mikrofluidik
(2011)
Trace-elements are more significant for provenancing archaeological metallic artifacts than the main components. For gold, the most promising elements are platinum group elements (PGE), Sn, Te, Sb, Hg and Pb. Several small fragments of natural Transylvanian gold placer and primary were studied by using micro-PIXE technique at the Legnaro National Laboratory AN2000 microbeam facility, Italy and at the AGLAE accelerator, C2RMF, Paris, France and by using micro synchrotron radiation X-ray fluorescence (micro-SR-XRF) at BESSY synchrotron, Berlin, Germany. The goal of the study was to identify the trace-elements, especially Sn, Sb and Te. A spectacular application to five Dacian gold bracelets authentication is presented (Sn and Sb traces).
Miscanthus x giganteus energy crop grown in Ireland was harvested on 21st of February and 28th of March 2012 to examine the effects of harvesting time on self-heating during storage of Miscanthus chips in clamps (98 m³) under weather sheltered conditions. There was a relatively large difference in moisture content, of 21.4%, between Miscanthus crop harvested in February and March (41.6 and 20.2%, respectively). Temperature evolution over a storage period of up to 125 days was monitored at different heights and distances from the centre within the clamps. Maximum temperature in the February constructed clamp reached 69 °C compared to 28 °C in the March constructed clamp. Microbial activity was monitored via carbon dioxide and oxygen gas measurements. The high moisture clamp showed higher microbial activity and a volume yield loss of 4.3% due to decomposition in the top section of the clamp. Quality indices post-storage were also assessed. Calorific values from Miscanthus sampled 1 m below the top surface were similar after storage for both February and March constructed clamps, i.e. 18.52 and 18.70 MJ kg-1, respectively. A reliable assessment of self-heating in Miscanthus chip clamps has important consequences for both self-ignition risk and biomass quality.
A new setup is presented which enables simultaneous wide- and small-angle X-ray scattering (WAXS/SAXS) and Raman spectroscopic experiments during the synthesis of Mo-based mixed oxide catalyst precursors at the µ-spot beamline at the Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung (BESSY). Furthermore, we report about the separate monitoring of the same reactions under comparable conditions by simultaneous combined ATR/UVvis/Raman spectroscopic measurements. For testing the performance of both experimental setups two syntheses were described comprising the precipitation of metal molybdates by mixing solutions of metal nitrates and ammonium heptamolybdate. Additionally, the effect of H3PO4 admixture on precipitation was investigated. The combined evaluation of spectroscopic and WAXS/SAXS data allows the discrimination between different molybdate species appearing in solution and precipitate. Furthermore, these molybdate species could be assigned to separate phases of different crystallinity.
A new high-resolution detector setup for neutron imaging has been developed based on infinity-corrected optics with high light collection, combined with customized mounting hardware. The system can easily be installed, handled and fitted to any existing facility, avoiding the necessity of complex optical systems or further improved electronics (CCD). This is the first time optical magnification higher than 1:1 has been used with scintillator-based neutron detectors, as well as the first implementation of infinity corrected optics for neutron imaging, achieving the smallest yet reported effective pixel size of 3.375 µm. A novel transparent crystal scintillator (GGG crystal) has been implemented with neutrons for the first time to overcome limitations of traditional powder scintillators (Li6/ZnS, Gadox). The standardized procedure for resolution measurements with the Modulation Transfer Function (MTF) is summarized to facilitate comparison between instruments and facilities. Using this new detector setup, a resolution of 14.8 µm with a field of view of 6 mm × 6 mm has been achieved while maintaining reasonable count times. These advances open a wide range of new possible research applications and allow the potential for additional future developments.