TY - RPRT A1 - Auersch, Lutz T1 - Mitigation measures for ballasted tracks - sleepers, sleeper pads and substructure - Results from the finite element boundary element method N2 - The ground vibrations, which are generated by trains on different tracks, have been calculated by finite-element boundary-element models. The ballasted track is modelled in detail by the finite element method. The infinite soil is modelled by the boundary element method as a homogeneous or layered half-space. The track-soil system is coupled with a simple rigid mass model of the vehicle so that the vehicle-track interaction is completely included. Transfer functions are calculated in frequency domain without and with vehicle-track interaction, the compliance of the track and the mobilities of the soil at different distances from the track. Finally, the ratios between the ground vibration amplitudes with and without mitigation measure are calculated to quantify the effectiveness of the mitigation measure. Tracks with under sleeper pads have been investigated in a wide parameter study. The main parameters that influence the reduction of ground vibration are the stiffness of the under sleeper pad, the mass and the width of the sleeper. The softest sleeper pad yields the best reduction of the ground vibration. The influence of the sleeper mass is not as strong as the characteristic frequency is ruled by the mass of the sleeper and the mass of the wheelset as well. The influence of other parameters has been examined. The stiffness of the rail pads, the bending stiffness of the track, the stiffness of the ballast, the sub-soil, and the soil, and the layering of the soil. All these parameters show no or only a minor influence on the mitigation effect. As the standard isolated track, a track with an under sleeper pad of a stiffness of kS = 5 107 N/m has been chosen, which can also be expressed as a stiffness per area of kS ’’ = 7.4 107 N/m3 = 0.074 N/mm3. The resonance frequency for this pad stiffness is observed between 32 and 40 Hz. The reduction of the ground vibration is about vi,I /vi,U = 0.2 and 0.1 at 100 Hz. The reduction can be improved by softer sleeper pads. But the compliance of the track gets higher than tolerable. A possibility to use softer sleeper pads without increasing the static compliance of the track is their combination with wide sleepers. The softer sleeper pads under wider sleepers yield the same compliance of the track and a better reduction of the ground vibration. KW - Heavy sleeper KW - Under sleeper pad KW - Finite-element boundary-element method KW - Mitigation KW - Ground vibration KW - Ballasted track PY - 2011 SP - 1 EP - 81 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-56607 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Ferrero, Fabio A1 - Zeps, Robert T1 - Simulation and experimental determination of the self ignition of tetrafluoroethylene in a 100-dm³-autoclave N2 - The gaseous TFE is a monomer which is used to form PTFE, also known as Teflon®, by a polymerisation process at elevated conditions of temperature and pressure. TFE belongs to the group of chemically instable gases which are able to decompose under specific conditions releasing a huge amount of heat comparable to a gas explosion of flammable gases. Due to several incidents in PTFE – production plants the investigation of the safety related properties of TFE at elevated condition was necessary and resulted in a research project at BAM which is subsidized by the PlasticsEurope association. In a first stage the pressure dependence of the Minimum Ignition Temperature for Decomposition (MITD) was determined in the range of 0.5 MPa - 3 MPa in small autoclaves with volumes of 0.2 dm³ and 3 dm³. These results were used to validate the numerical model and were found to correlate quite well with the simulated values. Nevertheless the applicability had to be confirmed for larger volumes as well. Therefore a heat able 100-dm³-autoclave was constructed and build to determine the MITD in the range of 0.5 MPa to 1.1 MPa. T2 - 8th European Congress of Chemical Engineering CY - Berlin, Germany DA - 25.09.2011 KW - Ignition temperature KW - Self decomposition KW - MITD KW - TFE KW - Tetrafluoroehtylene PY - 2011 N1 - Das Poster hat den Adolf-Martens-Preis im Bereich "Safety Engineering" erhalten. - The poster was awarded the Adolf Martens Prize in the section "Safety Engineering". N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. AN - OPUS4-55754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maierhofer, Christiane A1 - Kind, Thomas A1 - Köpp, Christian A1 - Helmerich, Rosemarie T1 - CHEF - Cultural heritage protection against flooding N2 - CHEF provides knowledge about flood protection of cultural heritage objects and directly supports the European Floods Directive by giving recommendations on how to assess the vulnerability of monuments. A comprehensive analysis of protective measures BEFORE, DURING and AFTER a flood has been carried out within the project, including technical and administrational measures. An overview of these measures is given, followed by recommendations on how to establish the most effective protective strategies. KW - Cultural heritage KW - Flood protection KW - Flood risks PY - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-385463 SP - 1 EP - 3 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-38546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabeza, Sandra A1 - Onorbe, Elvira A1 - Garces, Gerardo A1 - Perez, Pablo A1 - Klaus, Manuela A1 - Genzel, Christoph A1 - Adeva, Paloma T1 - The evolution of internal strain in Mg-Y-Zn alloys with a long period stacking ordered phase N2 - The load partition in Mg-Y-Zn system is studied by means of synchrotron diffraction. in-situ tensile tests disclose LPSO phases were for the first time proved to behave as an efficient reinforcement in Mg-Y-Zn alloys, therefore they could be treated as “short-fibre composite” for the modeling of mechanical behaviour. T2 - MECASENS CY - Grenoble, France DA - 16.09.2015 KW - Magnesium KW - LPSO KW - Synchrotron diffraction KW - Load partition PY - 2011 AN - OPUS4-38397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marinelli, F. A1 - Kuhlmann, S. I. A1 - Grell, E. A1 - Kunte, Hans-Jörg A1 - Ziegler, C. M. A1 - Faraldo-Gómez, J. D. T1 - Evidence for an allosteric mechanism of substrate release from membrane-transporter accessory binding proteins N2 - Numerous membrane importers rely on accessory water-soluble proteins to capture their substrates. These substrate-binding Proteins (SBP) have a strong affinity for their ligands; yet, Substrate release onto the low-affinity membrane transporter must occur for uptake to proceed. It is generally accepted that release is facilitated by the association of SBP and transporter, upon which the SBP adopts a conformation similar to the unliganded state, whose affinity is sufficiently reduced. Despite the appeal of this mechanism, however, direct supporting evidence is lacking. Here, we use experimental and theoretical methods to demonstrate that an allosteric mechanism of enhanced substrate release is indeed plausible. First, we report the atomic-resolution structure of APO TeaA, the SBP of the Na!-coupled ectoine TRAP transporter TeaBC from Halomonas elongata DSM2581T, and compare it with the substrate-bound structure previously reported. Conformational freeenergy landscape calculations based upon molecular Dynamics simulations are then used to dissect the mechanism that couples ectoine binding to structural change in TeaA. These insights allow us to design a triple mutation that biases TeaA toward apo-like conformations without directly perturbing the binding cleft, thus mimicking the influence of the membrane transporter. Calorimetric measurements demonstrate that the ectoine affinity of the conformationally biased triple mutant is 100-fold weaker than that of the wild type. By contrast, a control mutant predicted to be conformationally unbiased displays wild-type affinity. This work thus demonstrates that substrate release from SBPs onto their Membrane transporters can be facilitated by the latter through a mechanism of allosteric modulation of the former. KW - Binding thermodynamics KW - Periplasmic binding protein KW - Secondary transporter KW - ABC transporter KW - Replica-exchange metadynamics PY - 2011 U6 - https://doi.org/10.1073/pnas.1112534108 SN - 0027-8424 SN - 1091-6490 VL - 108 IS - 49 SP - E1285 EP - E1292 AN - OPUS4-37681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bremser, Wolfgang A1 - Tuma, Dirk A1 - Heine, H.-J. T1 - International reference values for calibration of process gas chromatographs (PGCs) and related uncertainties N2 - In a mutual framework agreement, the two German national institutes BAM (Federal Institute of Materials Research and Testing) and PTB (Physikalisch-Technische Bundesanstalt) agreed upon the development, provision, and dissemination of national measurement standards for chemical analysis via primary reference measuring systems. Traceability to national standards and international comparability is of key importance for the acceptance of measurement results in metrology. T2 - 6th International Gas Analysis Symposium & Exhibition -- GAS 2011 CY - Rotterdam, The Netherlands DA - 09.02.2011 KW - Metrology KW - Gas standards KW - Certification PY - 2011 AN - OPUS4-35943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merryweather, S. A1 - Zweifel, D. A1 - Woydt, Mathias ED - Franek, F. ED - Bartz, Wilfried J. ED - Pauschitz, A. ED - Vizintin, J. ED - Ciulli, E. ED - Crockett, R. T1 - Fuel economy of engine oils based on polyalkylene glycols N2 - The driver for automotive OEMs to work on alternative engine oils is the need for fuel economy and no adverse effect of the engine oil on the durability of particulate filters and catalysts. The alternative engine oils should for mid-term also comply with a positive environmental Profile. T2 - 3rd European Conference on Tribology and 4th Vienna International Conference on Nano-Technology CY - Vienna, Austria DA - 07.06.2011 KW - Biomotox KW - Head capacity KW - Fuel economy KW - Drain KW - Polyglycol KW - Polypropylene glycol KW - Polyalkylene glycol KW - Polybutylene glycol PY - 2011 SN - 978-3-901657-38-2 SP - 25 EP - 34 PB - MDH Media GesmbH CY - Wien AN - OPUS4-35671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Qian, H. A1 - Kalinka, Gerhard A1 - Chan, K.L.A. A1 - Kazarian, S.G. A1 - Greenhalgh, E.S. A1 - Bismarck, A. A1 - Shaffer, M.S.P. T1 - Mapping local microstructure and mechanical performance around carbon nanotube grafted silica fibres: Methodologies for hierarchical composites N2 - The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman maps of key features in the CNT spectra clearly show the CNT distribution and orientation, including a ‘parted’ morphology associated with long grafted CNTs. The hardness and indentation modulus of the epoxy matrix were improved locally by 28% and 24%, respectively, due to the reinforcing effects of CNTs. Moreover, a slower stress relaxation was observed in the epoxy region containing CNTs, which may be due to restricted molecular mobility of the matrix. The proposed methodology is likely to be relevant to further studies of nanocomposites and hierarchical composites. KW - Nanotubes KW - Silica fibres KW - Nano indentation KW - Mapping PY - 2011 U6 - https://doi.org/10.1039/c1nr10497g SN - 2040-3364 SN - 2040-3372 VL - 3 IS - 11 SP - 4759 EP - 4767 PB - RSC Publ. CY - Cambridge AN - OPUS4-34718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Sonderprüfverfahren für Verbundwerkstoffe T2 - Vortragsveranstaltung VDI-AK Kunststofftechnik, BV BB an der TU Berlin CY - Berlin, Deutschland DA - 2011-03-17 PY - 2011 AN - OPUS4-34456 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Oliver A1 - Christoph, Gabriele A1 - Kalbe, Ute A1 - Berger, Wolfgang T1 - Monitoring of PAH in aqueous samples - a comparison of different sample preparation techniques T2 - Environmental (Bio) Technologies CY - Gdansk, Poland DA - 2011-09-05 PY - 2011 AN - OPUS4-33661 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Ebell, Gino A1 - Burkert, Andreas A1 - Gehlen, C. A1 - Keßler, S. T1 - Validierung zerstörungsfreier Messmethoden zur zuverlässigen Erfassung von Bewehrungskorrosion (Schlussbericht) N2 - Determining a pore structure’s mechanical and chemical data on lime rendering exposed outdoors and including masonry in the laboratory, with regard to their behaviour on moisture transport and weathering was the objective. In search of clues for a dose-response relation - i.e. upon a connection between the emission rate of SO2 and NOx on one hand and the degree of damage to mainly plaster having a lime component on the other - it has been of interest to what extent their structural characteristics including pore space are modified and so consequently also physico-technical properties and chemical composition. For determining corresponding criteria, a widely diversified spectrum of test methods such as to obtain data concerning porosity and moisture transport, mechanical behaviour, and chemistry as well is available. A description of the manufacture of plate-shaped rendering specimens with lime putty, industrially hydrated lime and dolomitic hydrate (the last two also having a cement admixture) and also hydraulic lime as binding agents is included. First deposition velocity and absorption rate for SO2 were determined in laboratory tests on these materials in dry and moist states. After their exposure on outdoor racks at six locations in the Berlin region with differing SO2 atmospheric contents over at least 5 years, the samples of course show timedependent modifications of chemical and physical qualities which are especially reflected in the form of profiles of structure, strength and concentration, e.g. for sulphate. Local climatic differences, however, partly exert a greater influence on material than emissions. Similar investigations were performed on samples of comparable composition exposed 4 and 17 years. But the real surprise is furnished by the renderings’ behaviour depending upon orientation and upon height at a building. Since weathering behaviour and moisture Transport (absorption, storage, release) are directly interdependent, further criteria are necessary for a critical assessment of a plasters’ pore structure. Starting from sands, plasters were characterized. The structural parameters were lastly influenced by the respective contents of sand, binder and mixing water. These results and those gained from bricks naturally find their expression in masonry sections manufactured there from, and above all in their capillary and evaporative behaviours, and also when applying different test liquids. Summary and cited literature is given at the end of this report. KW - Potentialfeldmessung KW - Potential mapping KW - Korrosion KW - Stahlbeton KW - Betonstahl KW - Merkblatt B 3 PY - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-336229 SP - 1 EP - 92 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) / Technische Universität München AN - OPUS4-33622 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pulz, Robert A1 - Rehmer, Birgit T1 - Laser thermal shock experiments - performance and evaluation on the basis of advanced ceramics N2 - The thermal shock behaviour in air and vacuum of three different advanced ceramics is investigated by introducing a new testing method. This thermal shock testing system permits the reproducible setting of defined temperature profiles in thin disks. In order to perform heating - up thermal shock experiments under reproducible conditions and to measure the transient temperature fields, a laser beam is directed spirally across the surface of the specimen. In this process, the specimen is heated up faster than the temperature gradient is compensated by thermal conductivity. Resulting temperature fields were recorded space and time resolved. Based on the knowledge of the local temperature distribution at the moment of failure, the critical fracture stress can be calculated. The scatter of thermal shock strength is quantitatively determined for the tested ceramics by using a improved statistical method. KW - Thermal shock KW - Weibull statistics KW - Environmental media PY - 2011 U6 - https://doi.org/10.1088/1757-899X/18/20/202019 SN - 1757-899X N1 - Serientitel: IOP Conference Series: Materials Science and Engineering – Series title: IOP Conference Series: Materials Science and Engineering IS - Symposium 14 SP - 202019, 1 EP - 4 AN - OPUS4-33028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jochems, Frank T1 - Anerkennung von Sachverständigen für Prüfungen an Tanks und MEGC zur Beförderung gefährlicher Güter im Seeverkehr auf Grundlage des IMDG-Code - Zahlen, Daten und Ausblick T2 - Erfa Tanks und BK-Schüttgut-Container 2011 CY - BAM Berlin DA - 2011-10-20 PY - 2011 AN - OPUS4-32918 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosner, Martin A1 - Vogl, Jochen T1 - New offset Delta11B isotope reference materials for geochemical and environmental boron isotope studies N2 - The isotopic composition of boron is a well established tool in various areas of Science and industries. Boron isotope compositions are typically reported as 6"B values which indicate the isotopic difference of a sample relative to the internationally accepted isotope reference material NIST SRM 951. A significant drawback of all of the available boron isotope reference materials is that non covers a natural boron isotope composition apart from NIST SRM 951. PY - 2011 SN - 1471-8022 VL - 75 IS - 3 SP - 1755 PB - Mineralogical Society of Great Britain and Ireland CY - London AN - OPUS4-32684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen A1 - Pritzkow, Wolfgang T1 - Isotope reference materials for present and future isotope research N2 - The variation of isotope abundance ratios is increasingly used to unravell natural and technical questions. In the past the investigation and interpretation of such variations was the field of a limited number of experts. With new upcoming techniques and research topics in the last decades, such as provenance and authenticity of food, the number of published isotope data strongly increased. The development of inductively coupled plasma mass spectrometers (ICPMS) from an instrument for simple quantitative analysis to highly sophisticated isotope abundance ratio machines influenced this process significantly. While in former times only experts in mass spectrometry were able to produce reproducible isotope data, nowadays many laboratories, never been in touch with mass spectrometry before, produce isotope data with an ICPMS. Especially for such user isotope reference materials (IRM) are indispensible to enable a reliable method validation. The fast development and the broad availability of ICPMS also lead to an expansion of the classical research areas and new elements are under investigation. Here all users require IRM to correct for mass fractionation or mass discrimination or at least to enable isotope data related to a common accepted basis. Despite this growing interest suitable IRM are still lacking for a number of isotope systems such as magnesium. PY - 2011 SN - 1471-8022 VL - 75 IS - 3 SP - 2098 PB - Mineralogical Society of Great Britain and Ireland CY - London AN - OPUS4-32683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Hedrich, Martina A1 - Czichos, Horst ED - Czichos, Horst ED - Saito, T. ED - Smith, L. T1 - The development of RM activities and application examples N2 - Activities for the development of reference materials started as early as 1906 at the US National Bureau of Standards (NBS). In 1912, the first iron and steel reference materials were certified for carbon content in Germany by the Royal Prussian Materials Testing Institute MPA, predecessor of BAM, the Federal Institute for Materials Research and Testing. KW - Reference materials PY - 2011 SN - 978-3-642-16640-2 SP - Chapter 3.7.7, 105 EP - 107 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-32435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Portius, P. A1 - Filippou, A.C. A1 - Schnakenburg, G. A1 - Davis, M. A1 - Wehrstedt, Klaus-Dieter T1 - Taming the silicon tetraazide beast N2 - Highly energetic silicon tetraazide 1 is synthesized safely in high yield and high purity. The compound is prepared as a solution in benzene which allows it to be handled safely. Stable Lewis base adducts of Si(N3)4 (e.g. 2) are also prepared by treatment of either Si(N3)4 or the di­sodium salt of hexaazidosilicate (3) with Lewis bases (2,2-bipyridine or 1,10-phenanthroline). Unlike Si(N3)4 the Lewis base adduct 2 is thermally stable and does not decompose below 265 °C. The decomposition is very energetic (ΔHd = -2.4 kJg-1) which means 2 and related Lewis base ­adducts could replace environmentally harmful Pb(N3)4 used as primary explosive. KW - Highly energetic silicon tetraazide KW - Lewis base adducts KW - Azides KW - Silicon KW - Energetic materials PY - 2011 U6 - https://doi.org/10.1055/s-0030-1259150 SN - 1861-1958 VL - 1 SP - 0043 EP - 0043 PB - Thieme CY - Stuttgart AN - OPUS4-32352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosner, Martin A1 - Vogl, Jochen T1 - Three new offset Delta11B isotope reference materials for environmental boron isotope studies N2 - The isotopic composition of boron is a well established tool in various areas of Science and industry. Boron isotope compositions are typically reported as 5nB values which indicate the isotopic difference of a sample relative to the isotope reference material NIST SRM 951. A significant drawback of all of the available boron isotope reference materials is that none of them covers a natural boron isotope composition apart from NIST SRM 951. To fill this gap of required 5UB reference materials three new solution boric acid reference materials were produced, which cover 6096o of the natural boron isotope Variation (-20 to 40%oo B) of about 100%o. The new reference materials are certified for their B values and are commercially available through European Reference Materials® (http://wwrv.enn-cmi.org). The newly produced and certified boron isotope reference materials will allow straightforward method Validation and quality control of boron isotope data. T2 - International symposium on isotopes in hydrology, marine ecosystems and climate change studies CY - Monaco DA - 27.03.2011 KW - Boron KW - Boron isotope variations KW - Delta-scale KW - Stable isotopes KW - Isotope reference materials KW - Delta reference materials KW - Metrology in chemistry PY - 2011 SN - 978-92-0-135610-9 VL - 2 SP - 377 EP - 380 AN - OPUS4-31858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cruzado, A. A1 - Hartelt, Manfred A1 - Wäsche, Rolf A1 - Urchegui, M.A. A1 - Gómez, X. T1 - Fretting wear of thin steel wires. Part 2: Influence of crossing angle N2 - The wear behaviour of thin steel wires has been analyzed under oscillating sliding conditions in crossed cylinders contact geometry. The focus of this analysis was the influence of the crossing angle between the wires on the wear. The wires used had 0.45 mm in diameter and the material was cold-drawn eutectoid carbon steel (0.8% C) with a tensile strength higher than 2800 MPa. Two different types of tests were carried out, the first one representing the influence of the crossing angle for a constant load and the second one representing the influence of the crossing angle with constant contact pressure. In the first type of tests it was seen that as the contact angle decreases the contact pressure decreases too and hence less energy specific wear resistance is observed. As a consequence less wear is produced, thus increasing the life of the wires. In the second type of tests it was seen that with constant contact pressure but different crossing angles, nearly the same energy specific wear resistance was observed. This points at an identical wear behaviour in both type of tests but with a running-in and a steady state period as two different wear periods. The tests showed that the running in period may play an important role in the overall wear particle generation and hence the wear occurring in the steady state period is rather mild. KW - Fretting KW - Wires KW - Contact pressure KW - Crossing angle PY - 2011 U6 - https://doi.org/10.1016/j.wear.2011.04.012 SN - 0043-1648 VL - 273 IS - 1 SP - 60 EP - 69 PB - Elsevier CY - Amsterdam AN - OPUS4-31762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Kelling, Norbert T1 - Stribeck-type curves of alternative engine oils - Part I: Gray cast iron liners N2 - Wear tests are often used in engine development in order to characterize the functional profile of surfaces interacting with lubricants. This paper proposes a new test procedure to determine Stribeck-type curves for the tribosystem piston ring/cylinder liner involving test pieces prepared from engine components. The Variation of the friction coefficient with sliding speed depends on the structure and Constitution of the base oil, the viscosity index, the surface topography of the liner and ring, and the friction modifiers used. Novel organic friction modifiers of low molecular mass not only reduce the friction coefficients under mixed / boundary lubrication, but also in the fluid film regime. In addition, the influence of surface roughness on the wettability of surfaces can be significant for both static and dynamic wetting. For this reason, the interaction of the lubricant with the surfaces was also investigated to enable a correlation between the surface properties of the liquid and solid phases and the tribological behavior. T2 - 52. Tribologie-Fachtagung - Reibung, Schmierung und Verschleiß - Forschung und praktische Anwendungen CY - Göttingen, Deutschland DA - 26.09.2011 PY - 2011 SN - 978-3-00-035439-7 VL - Part I SP - 32/1 EP - 32/12 AN - OPUS4-31752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -