TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Mäder, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - The hoard of Becin - non-destructive analysis of the silver coins N2 - We report the results of an analytical investigation on 416 silver-copper coins stemming from the Ottoman Empire (end of 16th and beginning of 17th centuries), using synchrotron micro X-ray fluorescence analysis (SRXRF). In the past, analyses had already been conducted with energy dispersive X-ray fluorescence analysis (EDXRF), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM/EDX) and proton induced X-ray emission spectroscopy (PIXE).With this combination of techniques it was possible to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. For the interpretation of the data statistical analysis (principal component analysis—PCA) has been performed. A definite local assignment was explored and significant clustering was obtained regarding the minor and trace elements composing the coin alloys. KW - SRXRF KW - Silber KW - Archaeometrie PY - 2010 DO - https://doi.org/10.1007/s00339-010-5627-y SN - 0947-8396 VL - 99 IS - 2 SP - 351 EP - 356 PB - Springer CY - Berlin AN - OPUS4-23170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - Analysis of the hoard of Becin using X-ray-based techniques N2 - Four hundred and sixteen silver coins stemming from the Ottoman Empire (16th and 17th centuries) were analyzed to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. As most of the coins showed the typical green patina on their surfaces due to corrosion processes that have led to the depletion of copper in the near surface domains of the silver coins in comparison to their core composition, small samples had to be taken, embedded in synthetic resin, and cross sectioned to investigate the true-heart metal composition. µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission were applied to determine the silver contents as well as the minor and trace elements. The type of the alloy was investigated as well as if coins minted in different locations demonstrated homogeneous traits concerning the predominant impurities (Au and Bi), which could suggest a common ore. Finally, energy-dispersive microanalysis in a scanning electron microscope was applied to study the homogeneity/heterogeneity of the coins and the presence of surface enrichments and to explain differences between the µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission measurements concerning the main component. In general, the silver content of the analyzed specimen varies between 90 and 95%. These outcomes have not supported the historical interpretations, which predict that during the period studied, a debasement of approximately 44% of the silver content of the coins should have occurred. KW - SRXRF KW - Silber KW - BAMline PY - 2012 DO - https://doi.org/10.1002/xrs.2415 SN - 0049-8246 VL - 41 IS - 6 SP - 416 EP - 424 PB - Wiley CY - Chichester AN - OPUS4-27723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, J.P.C. A1 - Laím, L.M. A1 - Korzen, Manfred T1 - Fire behaviour of circular concrete columns with restrained thermal elongation N2 - Most of the previous studies on reinforced concrete columns with elastically restrained thermal elongation were carried out on square, rectangular or '+'-shaped cross sections. The number of fire resistance tests on circular reinforced concrete columns with elastically restrained thermal elongation is still very small. In order to examine the influence of several parameters on the behaviour in fire of this type of columns several fire resistance tests were carried out. The parameters tested were the load and restraint level, slenderness of the column and longitudinal reinforcement ratio. In the fire resistance tests the specimens were exposed to the ISO 834 standard fire curve and the critical time (fire resistance) and temperature and failure modes were determined. The test results showed that the spalling phenomenon may occur in circular columns and so reducing its fire resistance. The increasing of the load level led to a reduction while the increasing of the longitudinal reinforcement ratio or the decreasing of the slenderness of the columns led to an increasing of their fire resistance. The restraint level might not be much relevant on the fire resistance of circular reinforced concrete columns. KW - Fire KW - Resistance KW - Concrete KW - Circular KW - Column KW - Restraining PY - 2014 DO - https://doi.org/10.3151/jact.12.289 SN - 1346-8014 VL - 12 IS - 9 SP - 289 EP - 298 CY - Tokyo AN - OPUS4-31611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Korzen, Manfred A1 - Rodrigues, J.P.C. A1 - Correia, A.M. ED - Kodur, V. ED - Franssen, J.-M. T1 - Composite columns made of partially encased steel sections subjected to fire T2 - 6th International conference "Structures in fire" CY - East Lansing, Michigan, USA DA - 2010-06-02 KW - Fire resistance KW - Thermal restraint KW - Composite steel-concrete columns KW - Substructuring method KW - Restraining frame PY - 2010 SN - 978-1-60595-027-3 SP - 341 EP - 348 PB - DEStech Publications, Inc. CY - Lancaster, PA, USA AN - OPUS4-22482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huismann, Sven A1 - Rodrigues, J.P.C. A1 - Korzen, Manfred ED - Joao Paulo Correia Rodrigues, ED - Gabriel Alexander Khoury, ED - Niel Peter Hoj, T1 - Damage and strength reduction of a high performance concrete due to thermomechanical stresses T2 - International Workshop "Fire Design of Condrete Structures - from materials modelling to structural performance" CY - Coimbra, Portugal DA - 2007-11-08 KW - High-performance concrete (HPC) KW - Compressive strength KW - Thermal cracking KW - Thermo mechanical stresses KW - Ultrasonic testing PY - 2008 SP - 141 EP - 148 AN - OPUS4-18174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - De la Cruz, M.H.C. A1 - Rodrigues, J.M. A1 - Couto, P.R.G. A1 - Da Cunha, V.S. A1 - Bremser, Wolfram T1 - Estimativa da incerteza de medicao em análise cromatográfica: abordagem sobrea quantificacao de carbamato de etila em cachaca N2 - The measurement uncertainty is useful to estimate the confidence of analytical results. Nowadays, a result without the uncertainty statement cannot be considered reliable, but the scientific literature still lacks examples of the estimate of the measurement uncertainty. This paper presents a practical and reliable description of the measurement uncertainty estimation of the analytical determination of ethyl carbamate in cachaça by GC-IDMS. The isotope dilution technique (ID) associated with GC-MS was used to improve the accuracy. The uncertainty estimated corresponds to 10% of the mass fraction of ethyl carbamate (115 ± 11) ng/g, which is in agreement with ppb level. KW - Uncertainty KW - Measurement uncertainty KW - Chromatography KW - Ethyl carbamate PY - 2010 SN - 0100-4042 VL - 33 IS - 7 SP - 1578 EP - 1584 PB - Sociedade Brasileira de Química CY - São Paulo AN - OPUS4-21958 LA - por AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Korzen, Manfred A1 - Rodrigues, J.P.C. A1 - Laím, L.M.S. T1 - Fire resistance tests on circular concrete columns N2 - Most of the previous studies on reinforced concrete columns with elastically restrained thermal elongation were carried out on square, rectangular or ‘+’-shaped cross sections. The fire resistance of these columns is probably more compromised than in circular columns due to the phenomenon of concrete detachment in the corners of the cross-section. In order to examine the influence of several parameters on the behaviour in fire of circular reinforced concrete columns with restrained thermal elongation, several fire resistance tests were carried out. The parameters tested were load, restraint level, slenderness of the column and the longitudinal reinforcement ratio. In the fire resistance tests the specimens were exposed to the ISO 834 Standard fire curve and the critical time and temperature and failure modes were determined. The test results mainly indicated that the spalling phenomenon may also occur in circular columns and so reducing its fire resistance. The restrained level might not so much relevant concerning the fire resistance of circular reinforced concrete columns. T2 - Interflam 2013 - 13th International fire science & engineering conference CY - Egham, Surrey, UK DA - 24.06.2013 KW - Fire KW - Column KW - Concrete KW - Circular KW - Restraining PY - 2013 SN - 978-0-9556548-9-3 SP - 1119 EP - 1130 PB - Interscience Communications Limited AN - OPUS4-29695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Correia, A.M. A1 - Rodrigues, J.P.C. A1 - Korzen, Manfred T1 - Experimental research on the load-bearing capacity of partially encased steel columns under fire conditons N2 - The composite steel and concrete columns are known to have enhanced fire behaviour when compared with bare steel columns. However there are still aspects that must be clarified, as the influence of the building surrounding structure on the fire resistance of the columns. In this paper, the results of fire resistance tests on partially encased steel columns carried out with two different experimental systems are compared. In one of the experimental systems, the building surrounding structure is materialised by a steel restraining frame, and in the other is performed by the so-called substructuring method. Due to the concept of hybrid substructuring, the entire building is decomposed in two parts: one is represented by the building element under test, whereas the remaining building is simulated numerically in a computer. The main conclusion drawn from this work was that the surrounding structure has a major influence in the development of axial forces in the test columns. Moreover, it was observed that the higher the non-dimensional axial restraint ratio the lower the critical time of the columns. KW - Fire resistance KW - Thermal restraint KW - Composite steel-concrete columns KW - Substructuring method KW - Restraining frame PY - 2012 DO - https://doi.org/10.1260/2040-2317.3.1.81 SN - 2040-2317 VL - 3 IS - 1 SP - 81 EP - 94 PB - Multi-Science Publ. Co. CY - Brentwood AN - OPUS4-25632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -