TY - JOUR A1 - Reimers, Peter A1 - Goebbels, Jürgen T1 - New possibility of nondestructive evaluation by X-Ray computed tomography N2 - After the overwhelming breakthrough of medical computed axial tomography (CAT) in the 1970s, people at several places all over the world began to look for possible applications of this new picture-producing nondestructive testing method in the industrial field. At Bundesanstalt für Materialprüfung (BAM), Berlin, Federal Republic of Germany, the first experiments" with an EMI 5005-scanner were performed in 1978. In the wide field of nondestructiveevaluation (NDE), there were found several prominent examples that could be scanned successfully with thesoft (Ex< 120 keV) x-rays of a medical machine. Among These were impregnated wood, plastics, ceramics, light compound materials (noniron), and archaeological objects. PY - 1983 SN - 0025-5327 VL - 41 SP - 732 EP - 737 PB - Society for Nondestructive Testing CY - Columbus, Ohio, USA AN - OPUS4-40698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jungnikl, K. A1 - Goebbels, Jürgen A1 - Burgert, I. A1 - Fratzl, P. T1 - The role of material properties for the mechanical adaptation at branch junctions N2 - Branch junctions are mechanically particularly interesting areas of trees, because they have to withstand a combination of static and dynamic loads, from the stem as well as from the branch. In the present work, the local adaptation of material properties at branch junctions was assessed by mapping microfibril angle and tissue density. Images of the density distribution were obtained by computer tomography (CT). Wide angle X-ray scattering (WAXS) was used to determine the microfibril angle distribution with high-resolution around the junctions. The stem tissue around the junctions showed increased density and microfibril angle, which points towards an optimisation for fracture toughness. The tissue at the branch bases showed low density combined with high MFA, which provides deformability and flexibility and might act as protection of the stem against load transmission from the branch. KW - Branch junction KW - Computer tomography (CT) KW - Microfibril angle (MFA) KW - Notch stresses KW - Wide angle X-ray scattering (WAXS) PY - 2009 DO - https://doi.org/10.1007/s00468-008-0305-9 SN - 0931-1890 VL - 23 IS - 3 SP - 605 EP - 610 PB - Springer CY - Berlin ; Heidelberg AN - OPUS4-22887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stiller, M. A1 - Rack, A. A1 - Zabler, S. A1 - Goebbels, Jürgen A1 - Dalügge, O. A1 - Jonscher, S. A1 - Knabe, C. T1 - Quantification of bone tissue regeneration employing Beta-tricalcium phosphate by three-dimensional non-invasive synchrotron micro-tomography - A comparative examination with histomorphometry KW - Sinus floor augmentation KW - Histomorphometry KW - Synchrotron micro-tomography KW - Multi-dimensional microscopy KW - Histovolumetry PY - 2009 DO - https://doi.org/10.1016/j.bone.2008.10.049 SN - 8756-3282 VL - 44 IS - 4 SP - 619 EP - 628 PB - Elsevier CY - New York, NY, USA AN - OPUS4-22888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Enzmann, F. A1 - Kersten, M. A1 - Goebbels, Jürgen A1 - Meinel, Dietmar T1 - High-resolution X-ray tomography imaging of ivory KW - Ivory KW - High-resolution X-ray tomography KW - Elfenbein KW - Hochauflösende Röntgen-Computer-Tomographie PY - 2008 VL - 228 SP - 81 EP - 86 PB - BfN CY - Bonn AN - OPUS4-22889 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoferer, J. A1 - Hoffmann, L.M. A1 - Goebbels, Jürgen A1 - Last, G. A1 - Weil, W. A1 - Kasper, G. T1 - Reconstruction algorithms for the internal packing density distribution of fibrous filter media based on tomographic data N2 - Algorithms were developed to approximate the 3-dimensional internal packing density distributions of fibrous filter media at different levels of detail and complexity. Each algorithm uses certain input information derived from X-ray tomographic data of filter samples. Algorithm 1 creates a binary media structure consisting of the true (i.e. tomographically determined) void distribution plus regions of uniform packing density. The average packing density of the media is maintained constant. Algorithm 2 creates a model fibrous structure of straight fibres of equal diameter and random length positioned randomly in space, while maintaining the true (i.e. tomographically determined) fibre orientation distribution. The number and length of the fibres on average adds up to the packing density of the filter. The model fibrous structure is recreated by a stationary Poisson process of convex bodies. Algorithm 3 distributes pores of random size and location within a homogeneous matrix, such that the average packing density again coincides with the true (i.e. tomographically determined) packing density. This algorithm is also based on a stationary Poisson process of convex bodies. The capability of each algorithm to recreate the essential structural features of the media was tested against 'reality' by computing the respective overall pressure drop of the filter as well as the velocity distribution in the filter interior, and comparing with the results obtained for the 'true' packing density distribution of a sample measured by tomography. Compared to the assumption of a completely homogenous filter (which gives roughly 2 times the actual Δp), all algorithms are closer to reality. The binary algorithm deviates in Δp by a factor of 1.8; algorithm 3 comes within a factor of 1.6 of the true Δp. The best approximation is by algorithm 2 which narrows the difference in Δp to a factor of 1.4. KW - X-ray tomography KW - Fibrous filter KW - Packing density PY - 2009 SN - 1479-0602 VL - 9 IS - 2 SP - 147 EP - 154 PB - Filtration Solutions CY - Newbold, Coleorton, Coalville AN - OPUS4-22880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neugebauer, M. A1 - Hilpert, U. A1 - Bartscher, M. A1 - Gerwien, N. A1 - Kunz, S. A1 - Neumann, F. A1 - Goebbels, Jürgen A1 - Weidemann, Gerd T1 - Ein geometrisches Nomal zur Prüfung von Röntgen-Mikro-Computertomografiemesssystemen KW - Geometrische Normale KW - Röntgen-Mikro-Computertomografie KW - Dimensionelles Messen KW - Messgeräteprüfung KW - Geometrical standard KW - X-ray micro-computertomography KW - Dimensional measurement KW - Instrument testing PY - 2007 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 74 IS - 11 SP - 565 EP - 571 PB - Oldenbourg CY - München AN - OPUS4-22881 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidemann, Gerd A1 - Stadie, R. A1 - Goebbels, Jürgen A1 - Hillemeier, B. T1 - Computed tomography study of fibre reinforced autoclaved aerated concrete PY - 2008 SN - 0025-5300 VL - 50 IS - 5 SP - 278 EP - 285 PB - Hanser CY - München AN - OPUS4-22882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartscher, M. A1 - Neukamm, M. A1 - Hilpert, U. A1 - Neuschaefer-Rube, U. A1 - Härtig, F. A1 - Kniel, K. A1 - Ehrig, Karsten A1 - Staude, Andreas A1 - Goebbels, Jürgen T1 - Achieving traceability of industrial computed tomography KW - Industrial computed tomography (CT) KW - Coordinate metrology KW - Traceability PY - 2010 DO - https://doi.org/10.4028/www.scientific.net/KEM.437.79 SN - 1013-9826 VL - 437 SP - 79 EP - 83 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-20985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manke, I. A1 - Hartnig, C. A1 - Kardjilov, N. A1 - Riesemeier, Heinrich A1 - Goebbels, Jürgen A1 - Kuhn, R. A1 - Krüger, P. A1 - Banhart, J. T1 - In situ synchrotron X-ray radiography investigations of water transport in PEM fuel cells N2 - Water transport in an operating PEM fuel cell was investigated with synchrotron X-ray radiography with a spatial resolution of 3 µm and a temporal resolution of 5 s. This method allows for the detection of water accumulations with less than 10 µm diameter. We demonstrate that synchrotron X-ray imaging can dramatically expand the possibilities of imaging with high spatial and time resolution, especially as a complement to neutron radiography. Water transport processes from the first appearance of small water accumulations in the gas diffusion layer to their transport into the channel system were analysed in situ. Correlations between local effects such as water formation and operating conditions of the whole system, e.g. power variations, were found. A recently described eruptive water transport mechanism is analysed in detail. KW - Fuel cell KW - Gas diffusion layer KW - Imaging KW - Synchrotron KW - X-ray radiography KW - Two-phase flow KW - Water transport PY - 2010 DO - https://doi.org/10.1002/fuce.200800123 SN - 1615-6846 SN - 1615-6854 VL - 10 IS - 1 SP - 26 EP - 34 PB - Wiley-VCH CY - Weinheim AN - OPUS4-22730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brehme, Sven A1 - Schartel, Bernhard A1 - Goebbels, Jürgen A1 - Fischer, O. A1 - Pospiech, D. A1 - Bykov, Y. A1 - Döring, M. T1 - Phosphorus polyester versus aluminium phosphinate in poly(butylene terephthalate) (PBT): Flame retardancy performance and mechanisms N2 - Pyrolysis and fire behaviour of a phosphorus polyester (PET-P-DOPO) have been investigated. The glycol ether of the hydroquinone derivative of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was used as a reactive halogen-free flame retardant in PET-P-DOPO. PET-P-DOPO is proposed as an alternative to poly(butylene terephthalate) (PBT) with established halogen-free additives. It exhibits a high LOI (39.3%) and achieves V-0 classification in the UL 94 test. Three different mechanisms (flame inhibition, charring and a protection effect by the intumescent char) contribute to the flame retardancy in PET-P-DOPO and were quantified with respect to different fire risks. The fire load was reduced by 66% of the PBT characteristic. The reduction is the superposition of the relative reduction due to flame inhibition (factor 0.625) and charring (factor 0.545). The peak of heat release rate (pHRR) was reduced by 83% due to flame inhibition, charring and the protection properties of the char (factor 0.486). The strength of all three mechanisms is in the same order of magnitude. The intumescent multicellular structure enables the char to act as an efficient protection layer. PBT flame-retarded with aluminium diethylphosphinate was used as a benchmark to assess the performance of PET-P-DOPO absolutely, as well as versus the phosphorus content. PET-P-DOPO exhibits superior fire retardancy, in particular due to the additional prolongation of the time to ignition and increase in char yield. PET-P-DOPO is a promising alternative material for creating halogen-free flame-retarded polyesters. KW - Poly(butylene terephthalate) (PBT) KW - Fire retardancy KW - Aluminium phosphinate KW - 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) PY - 2011 DO - https://doi.org/10.1016/j.polymdegradstab.2011.01.035 SN - 0141-3910 SN - 1873-2321 VL - 96 IS - 5 SP - 875 EP - 884 PB - Applied Science Publ. CY - London AN - OPUS4-23469 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -