TY - CONF A1 - Marotzke, Christian A1 - Feldmann, Titus T1 - Limits in the determination of mechanical properties of composites by off-axis tests N2 - Off-axis tests are widely used for the determination of the anisotropic mechanical properties of composite materials, this is, the longitudinal E-modulus and the strength. The mechanical properties are evaluated from the test data under idealising assumptions such as homogeneity of the material as well as a homogeneous stress distribution. In real off-axis tests, however, significant deviations from the idealising assumptions are present. The reduction of the accuracy of the results strongly depends on the off-axis angle. In this paper a series of off-axis tests is analysed. The stresses on potential failure plane are calculated by finite element analyses. By varying the geometrical parameters it is shown how small deviations from the ideal case influence the measured elastic constants and the strength. Especially at low off-axis angles the mechanical properties strongly vary with the angle. In addition, fracture surfaces for different shear/normal stress combinations are studied and typical phenomena are identified. T2 - SEICO 14 - SAMPE Europe 35th International conference and forum CY - Paris, France DA - 10.03.2014 KW - Off-axis test KW - Composites KW - Strength KW - E-modulus PY - 2014 SN - 978-90-821727-0-6 IS - Session 5B SP - 293 EP - 300 AN - OPUS4-30376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Apel, Andreas A1 - Ballheimer, Viktor A1 - Kuschke, Christian A1 - Schubert, Sven A1 - Wille, Frank T1 - Approach for use of acceleration values for packages of radioactive material under routine conditions of transport N2 - The most relevant source of reference for load cases of packages for the transport of radioactive material under routine conditions is Appendix IV of the International Atomic Energy Agency (IAEA) Advisory Material TS-G-1·1. The acceleration values given there leave many questions open and have to be agreed upon with the involved competent authorities. Consequently, the actual load cases applied for a safety analysis may differ widely and could cause problems for international transport. To avoid such difficulties, it seems obvious that the according passages in TS-G-1·1 should be modified with the objective of making the load case data more consistent for a harmonized application in the IAEA member states. Papers pointing out in this direction were discussed at the PATRAM 2010 conference. The way to improve the acceleration data may lie in investigations and measurements considering, for example different types of vehicles and package masses. However, what should be the goal of such kind of surveys? Can such investigation provide values for every worldwide load case possible under routine conditions of transport? In particular, the different designs of vehicles give a reason to doubt that such an aim is realistic. The approach in this paper is to show that a less ambitious aim is more effective. Therefore, an approximate scheme is preferred, which renders better assistance in determining the appropriate acceleration values. KW - Radioactive materials KW - Safety assessment KW - IAEA regulations KW - Load cases KW - Routine conditions of transport KW - IAEA advisory material TS-G-1.1 KW - Appendix IV KW - Revision of load case data KW - Acceleration values PY - 2013 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 24 IS - 2 SP - 55 EP - 59 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-30378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kloß, Heinz A1 - Österle, Werner A1 - Dmitriev, A.I. ED - Bartz, Wilfried J. T1 - Modelling mechanical friction and wear behaviour using numerical results of the movable cellular automata (MCA) method N2 - In the mechanical friction and wear process, normal and tangential (shear) forces cause elastic and plastic deformations, generate cracks and form loose wear particles through fracture processes. Depending on the working conditions, the material properties and the real contact Situation (topography), a third body is formed as a mechanical ly mixed layer, which determines different running-in and steady-state behaviours. Two dimensional (2D) MCA Simulation results will be described via empirical equations, which are related to the incubation time (period without wear) and the following running-in wear rate (kinetic concept of strength, fatigue wear model). In order to understand the running-in and steady-state wear, kinetic model equations for mass balance of the third body are useful and are therefore to be included in the investigation. For a more complex material behaviour, numerical Simulation results are also presented for friction at the pad-disk interface of automotive brakes. T2 - 19th International colloquium Tribology - Industrial and automotive lubrication CY - Stuttgart/Ostfildern, Germany DA - 21.01.2014 PY - 2014 SN - 978-3-943563-10-8 SP - Paper 8.10, 1 EP - 7 CY - Stuttgart/Ostfildern AN - OPUS4-30437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hemmann, Felix A1 - Agirrezabal-Telleria, Iker A1 - Kemnitz, E. A1 - Jäger, Christian T1 - Probing slow chemical exchange of pyridine molecules at acid magnesium hydroxide fluoride surfaces by 15N NMR N2 - 15N NMR of pyridine has been used to study Lewis and Brønsted sites at the acid surface of magnesium hydroxide fluoride at two different pyridine loadings with ratios of excess pyridine compared to pyridine molecules bound to Lewis and Brønsted sites of about 1:1 (highly loaded) and 0.15:1 (low loaded), respectively. The Lewis and Brønsted sites can be distinguished by the 15N chemical shift of pyridine at about –100 ppm (LPy) and –175 ppm (BPy). In both samples a very broad 15N resonance is found around –88 ppm assigned to weakly adsorbed (excess) pyridine molecules via hydrogen bridges (HPy). Additionally, another signal at about –49 ppm is observed in the highly loaded sample only representing physisorbed pyridine (PPy). A slow chemical exchange process of strongly bound LPy and BPy molecules with excess HPy and PPy molecules can be monitored using 15N exchange NMR. It takes place on a time scale of about 50–100 ms at room temperature. All pyridine molecules have the same 15N T1 and its value increases from 800 ms (highly loaded sample) to 5.3 s (low loading) hinting on changed pyridine mobility depending on the loading level. KW - Catalysis KW - Acid surfaces KW - 15N NMR KW - Chemical exchange KW - Pyridine PY - 2014 DO - https://doi.org/10.1021/jp405213x SN - 1932-7447 SN - 1089-5639 VL - 117 IS - 28 SP - 14710 EP - 14716 PB - Soc. CY - Washington, DC AN - OPUS4-30439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Wolfgang A1 - Torge, Manfred A1 - Adam, Karin A1 - Römich, H. A1 - Weissmann, R. A1 - Drewello, R. T1 - Science in the service of restoration N2 - Stained glass is a particularly sensitive medium that in many churches has stillnot received sufficient protection against destructive influences of many andvarious kinds. Over long periods of time, nearly all materials are subject tochemical and physical change. The dramatic scale on which the processes of decayoften occur results from the influence of corrosive gases that are part of themix of today’s atmosphere. A basic requirement in the preservation of anyhistorical monument is therefore interdisciplinary collaboration; only the jointefforts of art historians, restorers and technicians, as well as scientists,offer a chance to protect our artistic and cultural heritage from decline. Measures to protect, conserve and restore stained glass are carried out by glassstudios. The project on which this chapter reports provides support for thispractical work through scientific back-up. In order to clarify what are verycomplex issues, a brief explanation of the scientific/technical context followshere, to preface the exposition of the basic questions posed. KW - Historische Glasmalereien KW - Restaurierung KW - Mikroorganismen PY - 2014 UR - http://www.cvma.ac.uk/conserv/mould.html SN - 1752-0741 SP - 1 EP - 44 PB - CVMA AN - OPUS4-30440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Probst, C. A1 - Erning, Johann Wilhelm T1 - Ist die Sanierung von Trinkwasserleitungen mit Epoxidharz ein unbedenkliches Verfahren? N2 - Trinkwasseranlagen in Neubauten funktionieren in der ersten Zeit einwandfrei. Das Wasser ist klar, die Ventile sind leichtgängig und es fließt genug Wasser aus den Armaturen. Erst im Laufe der - längeren oder kürzeren - Betriebszeit treten Störungen auf. Braunes Wasser deutet auf Korrosionsvorgänge hin. Kommt nur wenig Wasser aus den Armaturen, ist das ein Hinweis auf Inkrustationen. Ein schleichender Prozess, der Jahre und Jahrzehnte dauern kann. Doch spritzt erst einmal Wasser aus der Leitung, muss zumindest das betroffene Teilstück saniert werden. Viel Dreck, ein vorübergehender Ausfall der Wasserversorgung und ein hoher Koordinationsaufwand entstehen immer dann, wenn sich die Leitungen unter Putz und in bewohnten Gebäuden befinden. Damit es zu einem Totalausfall erst gar nicht kommt, raten auf Sanierung von Trinkwasseranlagen spezialisierte Unternehmen zu einem Beschichtungsverfahren mit Epoxidharz: Die gesamte Installation wird mit diesem Stoff von innen ausgekleidet. Das Beschichtungsmittel Epoxidharz allerdings wird kontrovers diskutiert. Nach Meinung der Kritiker gehen von ihm viele Gefahren aus. Die Befürworter sehen das hingegen ganz anders. Wir haben zwei Vertreter gebeten, ihre Argumente zusammenzutragen. Ist die Sanierung mit Epoxidharz ein unbedenkliches Verfahren? KW - Trinkwasser KW - Werkstoffe KW - Metallabgabe PY - 2014 SN - 0177-3054 VL - 67 IS - 6 SP - 14 EP - 15 PB - Strobel CY - Arnsberg AN - OPUS4-30442 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jeromenok, J. A1 - Böhlmann, W. A1 - Jäger, Christian A1 - Weber, J. T1 - Carbon dioxide adsorption in Betulin-based micro- and macroporous polyurethanes N2 - Separation of CO2. Microporous polyurethane networks were prepared based on a renewable resource. Betulin, extracted from birch bark, is used as a structure-directing diol monomer in A3-B2 monomers. The resulting microporous networks show very promising CO2/N2 selectivities. The state of adsorbed CO2 is analyzed by in situ NMR spectroscopy, and pure physisorption is proven. The preparation of monolithic materials is demonstrated as well. KW - Carbon dioxide KW - Gas adsorption KW - Microporous polymers KW - Renewable resources KW - Solid state NMR spectroscopy PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-304431 DO - https://doi.org/10.1002/open.201200045 SN - 2191-1363 VL - 2 IS - 1 SP - 17 EP - 20 PB - Wiley-VCH-Verl. CY - Weinheim AN - OPUS4-30443 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silva, C.P. A1 - Lima, D.L.D. A1 - Schneider, Rudolf A1 - Otero, M. A1 - Esteves, V.I. T1 - Evaluation of the anthropogenic input of caffeine in surface waters of the north and center of Portugal by ELISA N2 - This study comprises the development of an enzyme-linked immunosorbent assay (ELISA) for the quantification of caffeine in complex aqueous matrices without any sample clean-up procedure. Salinity and dissolved organic matter were selected as potential interfering agents. The addition of a sample buffer containing bovine serum albumin (BSA) prior to the sample was found to decrease the influence of those interfering agents. The working range of the developed method was 0.1–100 µg L- 1. Quantification of caffeine was possible in 43 out of 51 real aqueous samples, at values between < LOD and 15 µg L- 1. Results correlate well with those obtained by LC–MS/MS. To the best of our knowledge this is the first study dealing with the quantification of caffeine in Portugal's surface waters. KW - Caffeine KW - Surface water KW - ELISA KW - Anthropogenic markers KW - Koffein KW - Eintrag KW - Oberflächenwasser KW - Gewässer KW - Abwasser KW - Antikörper KW - Immunoassay PY - 2014 DO - https://doi.org/10.1016/j.scitotenv.2014.01.120 SN - 0048-9697 VL - 479-480 SP - 227 EP - 232 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-30450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pereira, P.M.R. A1 - Carvalho, José Joao A1 - Silva, S. A1 - Cavaleiro, J.A.S. A1 - Schneider, Rudolf A1 - Fernandes, R. A1 - Tomé, J.P.C. T1 - Porphyrin conjugated with serum albumins and monoclonal antibodies boosts efficiency in targeted destruction of human bladder cancer cells N2 - The synthesis of a novel PS conjugated with bovine and human serum albumin (BSA and HSA) and a monoclonal antibody anti-CD104 is reported, as well as their biological potential against the human bladder cancer cell line UM-UC-3. No photodynamic effect was detected when the non-conjugated porphyrin was used. Yet, when it was coupled covalently with the mAb anti-CD104, BSA and HSA, the resulting photosensitizer conjugates demonstrated high efficacy in destroying the cancer cells, the mAb anti-CD104 efficacy overruling the albumins. KW - Rinderserumalbumin KW - BSA KW - Monoklonale Antikörper KW - Blasenkrebs KW - Konjugate KW - Conjugates KW - Therapeutische Antikörper KW - CD104 PY - 2014 DO - https://doi.org/10.1039/c3ob42082e SN - 1477-0520 SN - 1477-0539 VL - 12 IS - 11 SP - 1804 EP - 1811 PB - RSC CY - Cambridge AN - OPUS4-30451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Beier, H.T. T1 - A model for fracture mechanics based prediction of the fatigue strength: Further validation and limitations N2 - Recently two of the authors of the present paper proposed a model for a fracture mechanics based prediction of the S–N characteristics of metallic components with large microstructural defects and supported this by a validation exercise on tensile plates made of an aluminium alloy AL5380 H321. Here the authors extend the study using a number of further data sets from the literature for which data were available at different R ratios. These data include two aluminium alloys, Al 2024-T3 and Al 7075-T6, and a ductile cast iron, EN-GJS- 400-18-LT. Despite of necessary assumptions for the compensation of partially missing input information the results were fairly reasonable with the exception of one data set. The authors identify high applied stress levels in combination with potential multiple crack initiation as the probable root of the problem and propose a scheme how the model can be extended for taking into account crack initiation. KW - Fatigue strength KW - S–N curve KW - Fracture mechanics KW - Crack propagation KW - Short cracks PY - 2014 UR - http://ac.els-cdn.com/S0013794413003901/1-s2.0-S0013794413003901-main.pdf?_tid=1403b676-b8a0-11e3-9087-00000aab0f26&acdnat=1396248522_d8c91133aa860e68196d9325c22ce651 DO - https://doi.org/10.1016/j.engfracmech.2013.12.005 SN - 0013-7944 SN - 1873-7315 SP - 1 EP - 17 PB - Elsevier Science CY - Kidlington AN - OPUS4-30452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -