TY - JOUR A1 - Nusser, K. A1 - Mosbauer, T. A1 - Schneider, G. J. A1 - Brandt, K. A1 - Weidemann, Gerd A1 - Goebbels, Jürgen A1 - Riesemeier, Heinrich A1 - Göritz, D. T1 - Silica dispersion in styrene butadiene rubber composites studied by synchrotron tomography N2 - By means of synchrotron X-ray computed tomography, model composites consisting of silica and styrene–butadiene rubber were studied with a very high spatial resolution. By our analysis technique we were able to determine the nano- and micro dispersion from the experimental results by our numerical analysis. These results are discussed with respect to crucial advantages of the generically 3-dimensional tomography technique as compared to 2-dimensional methods. Our quantitative analysis of the 3d images demonstrates that in the case of our model composites the filler dispersion is good, independent on the filler concentration. Our new 3-dimensional results evidence that considering only 2-d pictures may lead to ambiguities that can lead to wrong conclusions. KW - X-ray tomography KW - Silica KW - Styrene butadiene rubber KW - Dispersion PY - 2012 DO - https://doi.org/10.1016/j.jnoncrysol.2011.10.009 SN - 0022-3093 VL - 358 IS - 3 SP - 557 EP - 563 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-26105 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 - 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 - CONF A1 - Ehrig, Karsten A1 - Bartscher, M. A1 - Goebbels, Jürgen A1 - Härtig, F. A1 - Kniel, K. A1 - Neukamm, M. A1 - Neuschaefer-Rube, U. A1 - Staude, Andreas ED - Denecke, M. ED - Walker, C. T1 - Dimensional control of micro components with synchrotron computed tomography T2 - 20th International congress on X-ray optics and microanalysis CY - Karlsruhe, Germany DA - 2009-09-14 KW - Synchrotron radiation KW - Computed tomography KW - Dimensional measurement KW - Micro components PY - 2010 SN - 978-0-7354-0764-0 SN - 0094-243X SP - 164 EP - 171 PB - American Institute of Physics AN - OPUS4-21293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rack, A. A1 - Stiller, M. A1 - Nelson, K. A1 - Knabe, C. A1 - Rack, T. A1 - Zabler, S. A1 - Dalügge, O. A1 - Riesemeier, Heinrich A1 - Cecilia, A. A1 - Goebbels, Jürgen T1 - Ex vivo and in vitro synchrotron-based micro-imaging of biocompatible materials applied in dental surgery N2 - Biocompatible materials such as porous bioactive calcium phosphate ceramics or titanium are regularly applied in dental surgery: ceramics are used to support the local bone regeneration in a given defect, afterwards titanium implants replace lost teeth. The current gold standard for bone reconstruction in implant dentistry is the use of autogenous bone grafts. But the concept of guided bone regeneration (GBR) has become a predictable and well documented surgical approach using biomaterials (bioactive calcium phosphate ceramics) which qualify as bone substitutes for this kind of application as well. We applied high resolution synchrotron microtomography and subsequent 3d image analysis in order to investigate bone formation and degradation of the bone substitute material in a three-dimensional manner, extending the knowledge beyond the limits of classical histology. Following the bone regeneration, titanium-based implants to replace lost teeth call for high mechanical precision, especially when two-piece concepts are used in order to guaranty leak tightness. Here, synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in these kind of highly attenuating objects. Therefore, we could study micro-gap formation at interfaces in two-piece dental implants with the specimen under different mechanical load. We could prove the existence of micro-gaps for implants with conical connections as well as to study the micromechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential issue of failure, i. e. bacterial leakage which can induce an inflammatory process. T2 - SPIE Conference 7804 - Developments in X-ray tomography VII CY - San Diego, CA, USA DA - 2010-08-02 KW - Microtomography KW - Synchrotron radiation KW - Radiography KW - Dental implants KW - Bioceramics KW - Implant-abutment interface PY - 2010 DO - https://doi.org/10.1117/12.858435 SN - 0277-786X N1 - Serientitel: SPIE proceedings series – Series title: SPIE proceedings series VL - 7804 SP - 78040E-1 - 78040E-8 AN - OPUS4-22731 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernhardt, R. A1 - Scharnweber, D. A1 - Müller, B. A1 - Thurner, P. A1 - Schliephake, K. A1 - Wyss, P. A1 - Beckmann, F. A1 - Goebbels, Jürgen A1 - Worch, H. T1 - Comparison of microfocus- and synchrotron X-ray tomography for the analysis of osteointegration around T16AL4V-implants N2 - Micro-computed tomography (µCT) provides quantitative three-dimensional information of bone around titanium implants similar to classical histology. The study, based on an animal model, using cuboid-shaped biofunctionalised Ti6Al4V implants with surrounding bone after 4 weeks, is performed using 3 µCT-systems with X-ray tubes, one synchrotron-radiation-based µCT-system (SRµCT), and classical histology. Although the spatial resolution of the µCTsystems is comparable, only the results of SRµCT agree with results of classical histology. The X-ray tube sources give rise to huge artefacts in the tomograms (interface scattering, beam hardening), which impaired the quantitative analysis of bone up to about 200 µm from the implant surface. Due to the non-destructive character of µCT the specimens can be subsequently examined by classical histology without restriction. The quantitative comparison of bone formation uncovers the strong dependence of the detected amount of newly formed bone from the selected slice. This implies the necessity of 3D analysis. SRµCT and classical histology prove that surface modifications of the titanium implant significantly influence the bone formation. Using SRµCT, the preparation artefacts due to cutting and polishing are excluded. KW - X-ray micro computed tomography KW - Comparison of microfocus and synchrotron radiation KW - Osteointegration KW - Surface modification of titanium implants KW - Histology KW - Bone segmentation KW - Quantification of bone formation PY - 2004 UR - http://www.ecmjournal.org/journal/papers/vol007/vol007a05.php SN - 1473-2262 VL - 7 SP - 42 EP - 51 PB - Univ. of Wales CY - Aberystwyth, Wales AN - OPUS4-5600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Müller, K. A1 - Staude, Andreas A1 - Goebbels, Jürgen A1 - Riesemeier, Heinrich T1 - Synchrotron radiation and laboratory micro X-ray computed tomography - useful tools for the material identification of prehistoric objects made of ivory, bone or antler N2 - Archaeological bone, ivory and antler, as well as objects manufactured from them, are largely studied to extract as much information as possible from these materials. Among others, one key question in archaeology is the exact identification of the material. Even if the identification of different kinds of osseous material seems to be trivial in many cases, it can be a difficult issue when small, heavily carved and more or less altered ancient objects are concerned. This study was focused on the determination of parameters allowing the distinction of archaeological ivory, bone and antler in order to identify the raw material used for the manufacture of prehistoric objects. The high performance of synchrotron radiation (SR) and laboratory-based micro X-ray computed tomography (microCT), providing highly resolved three-dimensional information on the micromorphology, permitted the establishment of such distinctive features of modern references of ivory, antler, land mammal and whale bones: ivory shows characteristic tubular pores with a diameter of about 1 to 2 µm, bone and antler show typical osteon structures. In our measured references, antler shows on average larger and more elongated shaped pores of the osteons compared to terrestrial mammal bone. This feature however depends very much on the original localization of the studied sample within the antler. Whale bones can be distinguished from the other osseous materials by a cancellous, osteoporotic-like structure with irregularly distributed rounded porosities with diameters reaching up to 500 µm. These characteristics have also been tested on determined Palaeolithic fragments, as diagenetic changes during burial have to be considered and may lead to the modification of the parameters established on the basis of modern bone references. In general, the chemical composition of bone objects can change drastically over time while micromorphological features, as evidenced by microCT, seem to be less susceptible to such alterations. In addition, microCT enables the comparison of inner and possibly less altered parts of the objects, and can be considered as completely non-destructive for small mineralised prehistoric objects. In this study, specific morphological features allowing the distinction of ivory and of whale bone from other bone and antler material were determined, even for altered materials dating back to Palaeolithic periods. Thus, we provide, in addition to archaeozoological, chemical and isotopic markers, a new non-destructive tool to identify some raw materials used for the fabrication of osseous objects ranging from recent to prehistoric periods. PY - 2011 DO - https://doi.org/10.1039/c0ja00246a SN - 0267-9477 SN - 1364-5544 VL - 26 IS - 9 SP - 1802 EP - 1812 PB - Royal Society of Chemistry CY - London AN - OPUS4-24338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Siitari-Kauppi, M. A1 - Marcos, N. A1 - Klobes, Peter A1 - Goebbels, Jürgen A1 - Timonen, J. A1 - Hellmuth, K.-H. T1 - The Palmottu natural analogue project - physical rock matrix characterisation KW - C14-PMMA-Imprägnations-Radiographie KW - Hg-Porosimetrie KW - Computertomographie KW - Optische Mikroskopie KW - He-Diffusion KW - MMA-Diffusion KW - Wassersättigung PY - 2003 SN - 0783-3555 SP - 1 EP - 63 PB - Espoo AN - OPUS4-5194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hellmuth, K.-H. A1 - Siitari-Kauppi, M. A1 - Klobes, Peter A1 - Meyer, Klaus A1 - Goebbels, Jürgen T1 - Imaging and Analyzing Rock Porosity by Autoradiography and Hg-porosimetry/X-ray Computertomography-Applications N2 - The application of two sets of methods for the characterization of rock pore systems is reported. Both are discussed in the context of other techniques described in the literature. (i) Impregnation with labelled polymethylmethacrylate (PMMA) and autoradiography or direct measurement of the tracer activity allows the investigation of the pattern of the spatial porosity distribution and quantitative measurement of mineral-specific, local porosities, porosity gradients as well as an assessment of hydraulic and diffusive transport properties. (ii) Quantitative information on surface areas within certain pore size ranges can be achieved by combination of mercury intrusion porosimetry with X-ray absorption computertomography. As examples of applications of these techniques, the effects of weathering, alteration, mechanical stress and large diameter coring on the pore network of rocks have been studied. PY - 1999 SN - 1464-1895 VL - 24 IS - 7 SP - 569 EP - 573 PB - Pergamon CY - Oxford AN - OPUS4-11980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klobes, Peter A1 - Riesemeier, Heinrich A1 - Meyer, Klaus A1 - Goebbels, Jürgen A1 - Hellmuth, k.-H. T1 - Rock porosity determination by combination of X-ray computerized tomography with mercury porosimetry N2 - Abstract First results are described of coupling of mercury porosimetry with X-ray computerized tomography (CT) as a new combination technique for rock porosity studies. This technique is suitable for rock samples with a pronounced mercury intrusion-extrusion hysteresis and includes CT measurements before and after mercury intrusion. The entrapped portion of mercury, when the pressure after the intrusion into the rock sample is reduced to 0.1 MPa, serves as a contrast agent in the porous network to localize spatial distribution of rock porosity by CT. The results obtained show that the mercury intrusion and therefore the porosity were quite different for the separate mineral phases. Therefore the combination of mercury porosimetry and computer tomography can give 3-D data on mineral-specific porosity distributions with additional pore size information. In contrast to mercury porosimetry as a single method, results of the combination technique with CT represent a direct visualization of porosity variation and do not depend on any special pore network model. PY - 1997 SN - 0937-0633 VL - 357 IS - 5 SP - 543 EP - 547 PB - Springer CY - Berlin AN - OPUS4-11970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -