TY - JOUR A1 - Moser, Marko A1 - Schneider, Ralf A1 - Behnke, Thomas A1 - Schneider, Thomas A1 - Falkenhagen, Jana A1 - Resch-Genger, Ute T1 - Ellman’s and aldrithiol assay as versatile and complementary tools for the quantification of thiol groups and ligands on nanomaterials N2 - Simple, fast, and versatile methods for the quantification of thiol groups are of considerable interest not only for protein analysis but also for the characterization of the surface chemistry of nanomaterials stabilized with thiol ligands or bearing thiol groups for the subsequent (bio-) functionalization via maleimide−thiol chemistry. Here, we compare two simple colorimetric assays, the widely used Ellman’s assay performed at alkaline pH and the aldrithiol assay executed at acidic and neutral pH, with respect to their potential for the quantification of thiol groups and thiol ligands on different types of nanoparticles like polystyrene nanoparticles, semiconductor nanocrystals (SC NC), and noble metal particles, and we derive criteria for their use. In order to assess the underlying reaction mechanisms and to obtain stoichiometry factors mandatory for reliable thiol quantification, both methods were studied photometrically and with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), thereby demonstrating the influence of different thiols on the reaction mechanism. Our results underline the suitability of both methods for the quantification of directly accessible thiol groups or ligands on the surface of 2D- and 3D-supports, here exemplarily polystyrene nanoparticles. Moreover, we could derive strategies for the use of these simple assays for the determination of masked (i.e., not directly accessible) thiol groups like disulfides such as lipoic acid and thiol stabilizing ligands coordinatively bound to Cd and/or Hg surface atoms of II/VI and ternary SC NC and to gold and silver nanoparticles. KW - Nanoparticles KW - Ligands KW - Ellman KW - Aldrithiol KW - Quantification PY - 2016 DO - https://doi.org/10.1021/acs.analchem.6b01798 SN - 0003-2700 SN - 1520-6882 VL - 88 IS - 17 SP - 8624 EP - 8631 PB - ACS Publications CY - Washington AN - OPUS4-37561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Thomas A1 - Vierneusel, B. A1 - Gradt, Thomas A1 - Tremmel, S. A1 - Wartzack, S. A1 - Szücs, Z. A1 - Arendt, I. T1 - Optimierte MoS2-PVD-Schichten für wechselnde Umgebungsbedingungen N2 - Der Festschmierstoff Molybdändisulfid ist insbesondere für Extremanwendungen ein gerne eingesetzter Werkstoff, problematisch ist jedoch der negative Einfluss von Feuchtigkeit. Bei mittels PVD-Verfahren abgeschiedenen MoS2-Schichten ergibt sich jedoch die Möglichkeit, durch Anpassung der Beschichtungsparameter vorwiegend basal ausgerichtete Schichten herzustellen, die auch an Luft ein verbessertes tribologisches Verhalten zeigen. N2 - The solid lubricant molybdenum disulfide is a well known material for extreme conditions, but Problems arise due to a negative effect of humidity. However, by using a PVD process, deposition parameters can be optimized to gain coatings with a more textured structure orienting the basal planes parallel to the Substrate surface. Therefore, an improved tribological behavior even under moist conditions can be achievcd. KW - MoS2-coatings KW - PVD-process KW - Tribology KW - Moisture KW - Cryogenic temperatures KW - MoS2-Beschichtungen KW - PVD KW - Tribologie KW - Luftfeuchte KW - Kryogene Temperaturen PY - 2013 SN - 0724-3472 VL - 60 IS - 4 SP - 18 EP - 23 PB - Expert Verlag CY - Renningen AN - OPUS4-29995 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Thomas A1 - Gradt, Thomas A1 - Vierneusel, B. A1 - Tremmel, S. A1 - Wartzack, S. T1 - Tribological behavior of MoS2 in hydrogen environment N2 - The solid lubricant molybdenum disulfide is a well known material for extreme conditions where conventional oil or grease lubrication is not feasible (vacuum, high pressures). However, under reactive environments e.g. high humidity or hydrogen MoS2 is prone to premature failure. By using a PVD process, deposition parameters can be optimized to gain coatings with a more textured structure orienting the basal planes parallel to the Substrate surface, A similar concept has been used by Koch et al. for coatings developed to withstand the extreme operational conditions of the WENDELSTEIN W7-X fusion experiment. Therefore, an improved tribological behavior even under adverse conditions can be achieved. T2 - WTC 2013 - 5th World tribology congress CY - Torino, Italy DA - 08.09.2013 KW - Tribologie KW - Festschmierstoffe KW - MoS2 KW - Wasserstofftechnologie PY - 2013 SP - 1 EP - 3 AN - OPUS4-31156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Deutsch, Cornelius A1 - Gradt, Thomas A1 - Orts Gil, Guillermo A1 - Schneider, Thomas A1 - Dmitriev, A.I. T1 - Tribological screening tests for the selection of raw materials for automotive brake pad formulations N2 - A modified pin-on-disc test was applied to determine tribological properties of typical brake pad constituents. Ball-milling of these ingredients together with iron oxide and graphite provided model materials displaying the main features of real third bodies. Solid lubricants like graphite affected the friction and wear behaviour of Fe3O4 powders considerably whereas further addition of hard nanoparticles induced only minor effects. This was corroborated by comparison with modelling results. MoS2 played a dual role. Depending on special conditions, this ingredient either reduced or increased friction. The latter could be explained, after nanoscopic characterization, by oxidation and destruction of the wear-protecting tribofilm. KW - Brake pad formulation KW - Raw materials KW - Third body KW - Pin-on-disc test PY - 2014 DO - https://doi.org/10.1016/j.triboint.2014.01.017 SN - 0301-679X VL - 73 SP - 148 EP - 155 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-30221 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Deutsch, Cornelius A1 - Dörfel, Ilona A1 - Gradt, Thomas A1 - Häusler, Ines A1 - Orts-Gil, G. A1 - Prietzel, C. A1 - Schneider, Thomas T1 - Final outcome of a fundamental research project on tribofilms formed during automotive braking, Part 1: Experimental studies N2 - In order to obtain a better understanding of the role of tribofilms during automotive braking, their structures were investigated and the essential features identified. Next, different ingredient combinations were studied by preparing some model materials with simpler compositions than real tribofilms. A test method was developed for verifying the tribological properties of the model materials and for comparison with results obtained with numerical sliding simulations of such structures. Prerequisites of good brake Performance properties were identified. Although the coefficient of friction could be varied in a wide ränge, smooth sliding conditions could only be achieved with values smaller than 0.4. Tests with artificial third body powders turned out to be useful as screening method for the selection of raw materials for brake pad formulations. T2 - EuroBrake 2014 CY - Lille, France DA - 13.05.2014 KW - Tribofilm KW - Third body KW - Pad ingredients KW - Ball milling KW - Pin-on-disc test PY - 2014 SN - 978-0-9572076-4-6 SP - 1 EP - 8 PB - FISITA CY - London AN - OPUS4-35039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gradt, Thomas A1 - Aßmus, Kristin A1 - Börner, Helmut A1 - Schneider, Thomas T1 - Apparatus for friction tests of support elements in fusion devices N2 - Spacers and supports belong to the critical elements in the structure of a nuclear fusion device, particularly, when they are installed in the vacuum or superconducting magnet system of the reactor. These supports have to sustain high loads while allowing a certain amount of tangential movement with low friction and without any stick-slip motion. Vacuum and cryogenic environments are extremely hostile for smooth sliding systems, because conventional liquid lubricants cannot be employed, and only a very limited number of materials for dry sliding systems under these conditions are available. In order to test the friction behaviour of support elements in the field coils of the fusion experiment WENDELSTEIN 7-X, a test rig was build which allows testing in liquid helium environment at 4.2 K, with a normal force up to 150 kN, and a sliding velocity of 0.1 mm/s in oscillating motion. First tests have shown that the apparatus is appropriate for simulating the sliding behaviour of support elements. As an example, a result of an earlier model test of an MoS2-coating is shown. KW - Tribologie KW - Vakuum KW - Kernfusion KW - Festschmierstoffe PY - 2008 DO - https://doi.org/10.1088/1742-6596/100/6/062032 SN - 1742-6588 SN - 1742-6596 VL - 100 IS - 062032 SP - 1 EP - 4 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-17369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gradt, Thomas A1 - Schneider, Thomas A1 - Lingertat, J. A1 - Hathiramani, D. A1 - Junghanns, P. A1 - Aßmus, Kristin A1 - Schauer, F. T1 - Cryogenic vacuum tests of scaled down narrow support elements for the W7-X coil system KW - Wendelstein 7-X KW - Magnet system KW - Narrow support elements KW - Friction KW - MoS2 PY - 2009 DO - https://doi.org/10.1016/j.fusengdes.2008.11.075 SN - 0920-3796 VL - 84 IS - 2-6 SP - 840 EP - 843 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-19662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lingertat, J. A1 - Gradt, Thomas A1 - Hathiramani, D. A1 - Junghanns, P. A1 - Laux, M. A1 - Meine, Kerstin A1 - Schauer, F. A1 - Schneider, Thomas T1 - Tribological performance of MoS2 coatings in liquid helium and at high loads N2 - The main part of a narrow support element (NSE) of the W7-X superconducting coil system is an aluminium bronze pad, PVD coated on its spherical surface with MoS2, which slides against the flat surface of the stainless steel coil housing, coated with MoS2 spray. The operational requirements of the NSEs are: vacuum of p < 10-6 mbar, temperature T ~4 K, maximum load P ~1500 kN, typical displacement ≤5 mm, smooth sliding and no stick-slip events. The paper describes test results obtained with a downscaled NSE at T = 4.2 and 77 K. During the test the NSEs were submerged in liquid helium and nitrogen, respectively. Whereas the LN2 test ran smoothly for up to ~15,000 cycles, the test in LHe showed stick-slip from the very first cycle. The stick-slip disappeared after ~50 cycles. Post mortem analysis of the tested parts revealed that in case of LHe the sprayed MoS2 film was removed during the first 30-100 cycles by blistering and flaking. The reason for the loss of adhesion at LHe temperature is not known, several possible causes are under discussion. Further experiments under vacuum and at T ~4 K are being prepared which are expected to help in clarifying the issue. KW - Stellarator KW - Wendelstein 7-X KW - Mechanical structure KW - Narrow support elements KW - MoS2 KW - Lubrication KW - T=4K PY - 2009 DO - https://doi.org/10.1016/j.fusengdes.2009.01.069 SN - 0920-3796 VL - 84 IS - 7-11 SP - 1192 EP - 1196 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-19745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gradt, Thomas A1 - Schneider, Thomas A1 - Lingertat, J. A1 - Hathiramani, D. T1 - MoS2-Schmierung für hochbelastete Stützelemente zwischen supraleitenden Magnetspulen T2 - 49. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen CY - Göttingen, Deutschland DA - 2008-09-22 KW - Tribologie KW - Molybdändisulfid KW - Stick-Slip KW - Supraleitung KW - Kernfusion PY - 2008 SN - 978-3-00-025676-9 VL - I SP - 13/1 EP - 13/10 AN - OPUS4-18366 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gradt, Thomas A1 - Schneider, Thomas A1 - Lingertat, J. A1 - Hathiramani, D. A1 - Schauer, F. T1 - MoS2-Schmierung für hochbelastete Stützelemente zwischen supraleitenden Magnetspulen KW - Kernfusion KW - Supraleitende Magnete KW - Kryotribologie KW - Vakuumtribologie KW - Stick-Slip KW - MoS2 PY - 2009 SN - 0724-3472 VL - 56 IS - 5 SP - 24 EP - 28 PB - Expert Verlag CY - Renningen AN - OPUS4-20726 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vierneusel, B. A1 - Schneider, Thomas A1 - Tremmel, S. A1 - Wartzack, S. A1 - Gradt, Thomas T1 - Humidity resistant MoS2 coatings deposited by unbalanced magnetron sputtering N2 - MoS2 is a suitable solid lubricant for environments free of oxygen or water vapor (i.e. vacuum). Humid air degrades film properties due to oxidation accompanied by high wear and increasing coefficients of friction. The present study aims at the further development of sputtered pure MoS2 coatings, extending their applicability to varying environmental conditions by increasing the resistance against humidity. The systematic coating development process is supported by using an experimental Box–Behnken design with variations of the deposition parameters cathode voltage, target/substrate distance, temperature and argon gas pressure. In contrast to common one-factor-at-a-time (OFAT) studies, this approach enables a determination of interactions between deposition process parameters and tribological–mechanical MoS2 film properties. The tribological improvement focuses on a maximization of wear resistance in air and vacuum measured in ball-on-disk experiments. The evaluated mechanical properties are hardness, elastic modulus and residual stresses. These stresses were determined by the substrate curvature method. The study reveals that the residual stress state in the films and the hardness-to-modulus ratio are crucial for their tribological performance in humid air and vacuum environments. After a detailed determination of the relationships between deposition conditions and film properties, some selected microstructural analyses are presented which show that a substantially basal orientation of the lattice has positive effects on wear but also causes anisotropic film properties which result in fissile fracture of the coating if strong shock or point loads occur. KW - Unbalanced magnetron sputtering KW - MoS2 KW - Humidity resistance KW - Residual stress PY - 2013 DO - https://doi.org/10.1016/j.surfcoat.2013.07.019 SN - 0257-8972 VL - 235 SP - 97 EP - 107 PB - Elsevier B.V. AN - OPUS4-29729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Thomas A1 - Vierneusel, B. A1 - Gradt, Thomas A1 - Tremmel, S. A1 - Wartzack, S. A1 - Szücs, Z. A1 - Arendt, I. T1 - Optimierte MoS2-PVD-Schichten für wechselnde Umgebungsbedingungen N2 - Der Festschmierstoff Molybdändisulfid ist insbesondere für Extremanwendungen, bei denen konventionelle Öl- oder Fettschmierung nicht in Frage kommen (Vakuum, hohe Pressungen) ein gerne eingesetzter Werkstoff. Problematisch ist jedoch der negative Einfluss von Feuchtigkeit, wodurch die Einsetzbarkeit von M0S2 unter Normalbedingungen leidet. Bei mittels PVD-Verfahren abgeschiedenen MoSa-Schichten ergibt sich jedoch die Möglichkeit, durch Anpassung der Beschichtungsparameter vorwiegend basal ausgerichtete Schichten herzustellen, die auch an normal feuchter Luft ein verbessertes tribologisches Verhalten zeigen. MoSa-Schichten sind darüber hinaus auch für Anwendungen bei extrem tiefen Temperaturen interessant, da hier kein Schmierstoff zur Verfügung steht, der ähnlich günstige Reibeigenschaften aufweist. Für bewegliche Stützelemente zwischen supraleitenden Magnetspulen des Kernfusions-Experiments Wendelstein 7-X waren bis zu 7 pm dicke Schichten entwickelt worden, die jedoch durch das notwendige langsame Aufwachsen für andere Anwendungen nicht wirtschaftlich herzustellen waren. Hier sollen neue, im Rahmen eines Kooperationsprojekts entstandene MoS2-PVD-Schichten vorgestellt werden, die bei wechselnden Umgebungsbedingungen noch gute tribologische Eigenschaften liefern, jedoch durch ihre Dicke von 1-2 pm und hoher Aufwachsrate kostengünstig sind. N2 - The solid lubricant molybdenum disulfide is a well known material for extreme conditions where conventlonal oll or grease lubrication is not feasible (vacuum, high pressures). Problems arise due to a negative effect of humidity which is a drawback for the suitability of M0S2 under normal conditions. However, by using a PVD process, Deposition parameters can be optimized to gain coatings with a more textured structure orienting the basal planes parallel to the Substrate surface. Therefore, an improved tribological behavior even under moist conditions can be achieved. MoS2-coatings additionally are interesting candidates for being applied under cryogenic temperatures, since no lubricant is available having similarly favorable frictional properties. Up to 7 pm thick coatings have been developed especially for sliding support elements between superconducting magnets of the fusion-experiment Wendelstein 7-X, however, the extremely slow deposition rate precluded its utilization on more common tribo-systems due to cost considerations. Here, new MoS2-coatings are presented which were developed in a cooperational project, giving good tribological results under variing environments but are more cost effective being only 1-2 pm in thickness and faster in film growth.. T2 - 53. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß CY - Göttingen, Germany DA - 24.09.2012 PY - 2012 SN - 978-3-00-039201-6 SP - 46/1 EP - 46/12 CY - Aachen AN - OPUS4-26724 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gradt, Thomas A1 - Schneider, Thomas T1 - Tribological performance of MoS2 coatings in various environments N2 - Molybdenum disulfide (MoS₂) is a well-known solid lubricant for tribosystems running in vacuum or dry gases. Problems arise due to its sensitivity to humidity, which is a drawback for its application under ambient conditions. However, by using a physical vapor deposition (PVD) process, deposition parameters can be optimized not only to gain a coatings structure with favorable frictional properties but also to minimize the sensitivity to attack by water molecules. Therefore, an improved tribological behavior even under moist conditions can be achieved. MoS₂coatings are also candidates for being applied at cryogenic temperatures. They already have proven their suitability, e.g., for sliding support elements between superconducting magnets of the nuclear fusion-experiment Wendelstein 7-X. However, these coatings were exclusively produced for this particular application and the utilization for more common tribosystems may be precluded due to cost considerations. In view of a wider range of applications, pure and Cr containing PVD-MoS₂ coatings with an optimized structure were tested under varying environments including hydrogen gas and cryogenic temperatures. Results of the most promising variant are presented in this paper. KW - Solid lubrication KW - MoS2 KW - Extreme environments KW - Hydrogen KW - Cryogenic einvironment PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-381460 DO - https://doi.org/10.3390/lubricants4030032 SN - 2075-4442 VL - 32 IS - 4 PB - MPPI AG CY - Basel, Switzerland AN - OPUS4-38146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Thomas A1 - Schneider, Markus A1 - Schäpe, Kaija T1 - Classification of engineered Titania nanomaterials via surface analysis using principal component analysis (PCA) assisted Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) N2 - Due to the growing number of engineered nanomaterials (NM) the need for a reliable risk assessment for these materials is today bigger than ever before. Especially the nanomaterial’s surface or shell directly interacts with its environment and therefore is a crucial factor for NM’ toxicity or functionality. Especially, titania is one of the NM with the greatest technological importance. It is used for a large number of applications and can be found in food, cosmetics, glasses, mirrors, paints to mention only a few. In 2012, experts estimate[d] the annual European nano-titania production or utilization at an amount of more than 10,000 t. Great progress has been achieved in the area of NM investigation and characterization during the past decade. A variety of publications provide information about technological innovation as well as hazard potential, which means the potential risk on human health and ecosystems. However, enhanced data harmonization and well-defined standards for nanomaterial analysis, could significantly improve the reliability of such studies which often suffers from varying methods, parameters and sample preparations. To develop a suitable approach for the NM’s risk assessment, the ACEnano project aims at establishing a toolbox of verified methods. The size of this well-structured European project allows to handle even those big challenges like data harmonization and standardization. Due to its powerful combination of superior surface sensitivity and lateral resolution down to the Nano regime, ToF-SIMS could become one of these toolbox methods. Supported by multivariate data analysis such as principal component analysis (PCA), the method can be used for sub-classification of nanomaterial families using slight differences in surface chemistry. Here, we show a PCA supported classification of titania nanoparticles from various sources (NIST, JRC, BAM) with ToF-SIMS. Parameters like size, shell, pre-preparation and crystal system cause variance in the data and allow us to distinguish the species from each other. Moreover, this variance in the data also occurs and can be used for investigation when we compare our measurements of particle ensembles with those of grown titania films. The carefully selected and refined peaks allow a reasonable particle categorization and further a reliable allocation of blank feeds, which introduces a promising approach for NM characterization in the context of NM risk assessment. T2 - SIMS-Europe CY - Münster, Germany DA - 16.09.2018 KW - Nanoparticles KW - ToF-SIMS KW - XPS KW - PCA KW - Titania PY - 2018 AN - OPUS4-46250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Otto, A.H. A1 - Schrader, S. A1 - Steiger, Thomas A1 - Schneider, M. T1 - Gas-phase deprotonation energies of sulfuric acid, perchloric acid, chlorosulfuric acid and fluorosulfuric acid PY - 1997 SN - 0956-5000 VL - 93 IS - 22 SP - 3927 EP - 3930 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-2679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meine, Kerstin A1 - Kloß, K. A1 - Schneider, Thomas A1 - Spaltmann, Dirk T1 - The influence of surface roughness on the adhesion force N2 - Adhesion measurements are presented which were carried out with an atomic force microscope between polymer balls attached to a cantilever and a silicon wafer under ultra high vacuum conditions. In using a silicon surface with a defined structure a correlation between adhesion force and contact area was found. This correlation could partly be explained by the Johnson-Kendall-Roberts model, if a change of the surface energy is assumed as a result of the structuring. For a constant geometric contact area an additional structuring leads to a decrease of the adhesion force. T2 - 10th European Conference on Applications of Surface and Interface Analysis (ECASIA '03) CY - Berlin DA - 2003-10-05 KW - Roughness KW - Adhesion KW - AFM KW - UHV KW - JKR model KW - Surface energy PY - 2004 DO - https://doi.org/10.1002/sia.1738 SN - 0142-2421 SN - 1096-9918 VL - 36 IS - 8 SP - 694 EP - 697 PB - Wiley CY - Chichester AN - OPUS4-4708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Almagro, J.-F. A1 - Busch, P. A1 - Gohil, D. D. A1 - Saunders, S. R. J. A1 - Sloof, W. G. A1 - Thiot, J.-F. A1 - Schneider, H. A1 - Whitwood, M. A1 - Wirth, Thomas T1 - Electron-Probe MICROanalysis of LighT Elements - Measurement Methods and Certified Reference Materials (MICROLITE) PY - 2000 IS - 266 SP - 1 EP - 35 PB - National Physical Laboratory CY - Teddington, Middlesex AN - OPUS4-6843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -