TY - JOUR A1 - Klein, P. A1 - Zhang, Z. A1 - Friedrich, K. A1 - Theiler, Geraldine A1 - Hübner, Wolfgang T1 - Zur Bildung von Transferfilmen bei ausgewählten PTFE-Compounds KW - Wear KW - Transfer film KW - Polytetrafluoroethylene KW - Composites PY - 2003 SN - 0724-3472 VL - 50 IS - 4 SP - 32 EP - 36 PB - Expert Verlag CY - Renningen AN - OPUS4-12663 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, W. A1 - Gaggl, M. A1 - Gluth, Gregor A1 - Behrendt, F. T1 - Gas separation using porous cement membrane N2 - Gas separation is a key issue in various industrial fields. Hydrogen has the potential for application in clean fuel technologies. Therefore, the separation and purification of hydrogen is an important research subject. CO2 capture and storage have important roles in 'green chemistry'. As an effective clean technology, gas separation using inorganic membranes has attracted much attention in the last several decades. Membrane processes have many applications in the field of gas separation. Cement is one type of inorganic material, with the advantages of a lower cost and a longer lifespan. An experimental setup has been created and improved to measure twenty different cement membranes. The purpose of this work was to investigate the influence of gas molecule properties on the material transport and to explore the influence of operating conditions and membrane composition on separation efficiency. The influences of the above parameters are determined, the best conditions and membrane type are found, it is shown that cementitious material has the ability to separate gas mixtures, and the gas transport mechanism is studied. KW - Gas separation KW - Porous membrane KW - Clean fuel KW - Cement membrane KW - Inorganic membranes PY - 2014 DO - https://doi.org/10.1016/S1001-0742(13)60389-7 SN - 1001-0742 SN - 1878-7320 VL - 26 IS - 1 SP - 140 EP - 146 CY - Beijing, China AN - OPUS4-30039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gluth, Gregor A1 - Zhang, W. A1 - Gaggl, M. A1 - Hillemeier, B. A1 - Behrendt, F. T1 - Multicomponent gas diffusion in hardened cement paste at temperatures up to 350 °C N2 - Diffusional gas transport of a H2/CO2 mixture versus N2 in the pore system of hardened cement pastes was studied at four temperatures up to 350 °C in a Wicke-Kallenbach cell. The pastes possessed separation factors αH2,CO2 from 1.42 to 3.43, i.e. the diffusion of hydrogen took place considerably faster than the diffusion of carbon dioxide. The separation factors depended on the threshold radii of the pastes, smaller threshold radii leading to higher separation factors. The Knudsen numbers of the controlling constrictions of the pore system and the temperature dependence of the effective diffusion coefficients of the gases show that gas transport in these constrictions takes place in the transient regime between Knudsen diffusion and bulk diffusion, smaller constriction widths leading to predominating Knudsen diffusion. It is therefore possible to use cement paste membranes to separate gas components of low molecular weight from higher weight components. KW - Microstructure (B) KW - Mercury porosimetry (B) KW - Diffusion (C) KW - Cement paste (D) KW - Gas separation KW - Pore structure PY - 2012 DO - https://doi.org/10.1016/j.cemconres.2012.02.001 SN - 0008-8846 SN - 1873-3948 VL - 42 IS - 5 SP - 656 EP - 664 PB - Pergamon Press CY - New York, NY AN - OPUS4-25655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, L. A1 - Darvishi Kamachali, Reza A1 - Li, Z. A1 - Zhang, Z. T1 - Grain boundary energy effect on grain boundary segregation in an equiatomic high-entropy alloy N2 - Grain boundary (GB) Segregation has a substantial effect on the microstructure evolution and properties of polycrystalline alloys. The mechanism of nanoscale segregation at the various GBs in multicomponent alloys is of great challenge to reveal and remains elusive so far. To address this issue, we studied the GB segregation in a representative equiatomic FeMnNiCoCr high-entropy alloy (HEA) aged at 450 °C. By combining transmission Kikuchi diffraction, atom probe tomography analysis and a density-based thermodynamics modeling, we uncover the nanoscale segregation behavior at a series of well-characterized GBs of different characters. No segregation occurs at coherent twin boundaries; only slight nanoscale segregation of Ni takes place at the low-angle GBs and vicinal \Sigma 29b coincidence site lattice GBs. Ni and Mn show cosegregation of high levels at the general high-angle GBs with a strong depletion in Fe, Cr, and Co. Our density-based thermodynamic model reveals that the highly negative energy of mixing Ni and Mn is the main driving force for nanoscale cosegregation to the GBs. This is further assisted by the opposite segregation of Ni and Cr atoms with a positive enthalpy of mixing. It is also found that GBs of higher interfacial energy, possessing lower atomic densities (higher disorder and free volume), show higher segregation levels. By clarifying the origins of GB segregations in the FeMnNiCoCr HEA, the current work provides fundamental ideas on nanoscale segregation at crystal defects in multicomponent alloys. KW - Thermodynamics KW - High-Entropy Alloys KW - Grain Boundary Segregation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508827 DO - https://doi.org/10.1103/PhysRevMaterials.4.053603 VL - 4 IS - 5 SP - 053603 PB - American Physical Society AN - OPUS4-50882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Kim, C.S. A1 - Ruh, S. W. A1 - Unger, Wolfgang A1 - Radnik, Jörg A1 - Mata-Salazar, J. A1 - Juarez-Garcia, J.M. A1 - Cortazar-Martinez, O. A1 - Herrera-Gomez, A. A1 - Hansen, P.E. A1 - Madesen, J.S. A1 - Senna, C.A. A1 - Archanjo, B.S. A1 - Damasceno, J.C. A1 - Achete, C.A. A1 - Wang, H. A1 - Wang, M. A1 - Windover, D. A1 - Steel, E. A1 - Kurokawa, A. A1 - Fujimoto, T. A1 - Azuma, Y. A1 - Terauchi, S. A1 - Zhang, L. A1 - Jordaan, W.A. A1 - Spencer, S.J. A1 - Shard, A.G. A1 - Koenders, L. A1 - Krumrey, M. A1 - Busch, I. A1 - Jeynes, C. T1 - Thickness measurement of nm HfO2 films N2 - A pilot study for the thickness measurement of HfO2 films was performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study was to ensure the equivalency in the measurement capability of national metrology institutes for the thickness measurement of HfO2 films. In this pilot study, the thicknesses of six HfO2 films with nominal thickness from 1 nm to 4 nm were measured by X-ray Photoelectron Spectroscopy (XPS), X-ray Reflectometry(XRR), X-ray Fluorescence Analysis (XRF), Transmission Electron Spectroscopy (TEM), Spectroscopic Ellipsometry (SE) and Rutherford Backscattering Spectrometry (RBS). The reference thicknesses were determined by mutual calibration of a zero-offset method (Medium Energy Ion Scattering Spectroscopy (MEIS) of KRISS) and a method traceable to the length unit (the average thicknesses of three XRR data except the thinnest film). These reference thicknesses are traceable to the length unit because they are based on the traceability of XRR. For the thickness measurement by XPS, the effective attenuation length of Hf 4f electrons was determined. In the cases of XRR and TEM, the offset values were determined from a linear fitting between the reference thicknesses and the individual data by XRR and TEM. The amount of substance of HfO2, expressed as thickness of HfO2 films (in both linear and areal density units), was found to be a good subject for a CCQM key comparison. To reach the main text of this paper, click on Final Report. The final report has been peer-reviewed and approved for publication by the CCQM. KW - Thickness measurements KW - nm films KW - X-ray Photoelectron Spectroscopy KW - Mutual calibration PY - 2021 DO - https://doi.org/10.1088/0026-1394/58/1A/08016 SN - 0026-1394 VL - 58 IS - 1a SP - 08016 PB - IOP Publishing Lt. CY - Bristol AN - OPUS4-54175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A. P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.F. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J. L. A1 - Chen, J. A1 - Counsell, J..D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cartazar-Martínez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Shard, A.G. T1 - Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene N2 - We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Intensity scale calibration KW - Reference spectra KW - Low-density polyethylene (LDPE) PY - 2020 DO - https://doi.org/10.1116/6.0000577 VL - 38 IS - 6 SP - 063208 AN - OPUS4-51655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, S.J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A.P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.P. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J.L. A1 - Chen, J. A1 - Counsell, J.D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cortazar-Martinez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Compean-Gonzalez, C.L. A1 - Ceccone, G. A1 - Shard, A.G. T1 - ERRATUM: “Versailles project on advanced materials and standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene” [J. Vac. Sci. Technol. A 38, 063208 (2020)] N2 - The lead authors failed to name two collaborators as co-authors. The authors listed should include: Miss Claudia L. Compean-Gonzalez (ORCID: 0000-0002-2367-8450) and Dr. Giacomo Ceccone (ORCID: 0000-0003-4637-0771). These co-authors participated in VAMAS project A27, provided data that were analyzed and presented in this publication (and supporting information), and reviewed the manuscript before submission. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Low-density polyethylene PY - 2021 DO - https://doi.org/10.1116/6.0000907 VL - 39 IS - 2 SP - 027001 PB - American Vacuum Society AN - OPUS4-52380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, M. A1 - Schlaich, C. A1 - Zhang, J. A1 - Donskyi, Ievgen A1 - Schwibbert, Karin A1 - Schreiber, Frank A1 - Xia, Y. A1 - Radnik, Jörg A1 - Schwerdtle, T. A1 - Haag, R. T1 - Mussel-inspired multifunctional coating for bacterial infection prevention and osteogenic induction N2 - Bacterial infection and osteogenic integration are the two main problems that cause severe complications after surgeries. In this study, the antibacterial and osteogenic properties were simultaneously introduced in biomaterials, where copper nanoparticles (CuNPs) were generated by in situ reductions of Cu ions into a mussel-inspired hyperbranched polyglycerol (MI-hPG) coating via a simple dip-coating method. This hyperbranched polyglycerol with 10 % catechol groups’ modification presents excellent antifouling property, which could effectively reduce bacteria adhesion on the surface. In this work, polycaprolactone (PCL) electrospun fiber membrane was selected as the substrate, which is commonly used in biomedical implants in bone regeneration and cardiovascular stents because of its good biocompatibility and easy post-modification. The as-fabricated CuNPs-incorporated PCL membrane [PCL-(MI-hPG)-CuNPs] was confirmed with effective antibacterial performance via in vitro antibacterial tests against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and multi-resistant E. coli. In addition, the in vitro results demonstrated that osteogenic property of PCL-(MI-hPG)-CuNPs was realized by upregulating the osteoblast-related gene expressions and protein activity. This study shows that antibacterial and osteogenic properties can be balanced in a surface coating by introducing CuNPs. KW - Mussel-inspired coating KW - CuNPs KW - Multi-resistant bacteria KW - Antibacterial KW - Antifouling KW - Osteogenesis PY - 2021 DO - https://doi.org/10.1016/j.jmst.2020.08.011 SN - 1005-0302 VL - 68 SP - 160 EP - 171 PB - Elsevier Ltd. AN - OPUS4-51519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, Qiang A1 - Heuchel, Matthias A1 - Thünemann, Andreas A1 - Machatscheck, Rainhard T1 - The role of diffusion in the hydrolytic degradation of poly(lactic-co-glycolic acid): A molecular perspective N2 - This research emphasizes the importance of internal surface erosion as a key factor in the hydrolytic degradation of PLGA (poly(D,L-lactic-co-glycolic acid)) providing an alternative view of the established surface and bulk erosion degradation modes. Using molecular dynamics (MD) simulations, this study reveals the role of water and oligomer diffusion during the degradation of PLGA and highlights the importance of water channels formed as the overall water content increases. We found that these continuous water channels play a crucial role in accelerating the transport of water and the release of degradation products from the polymer matrix, as the diffusion coefficients of water and small oligomers exhibit significant differences spanning 2 to 3 orders of magnitude between the water and polymer phases. Water follows a different diffusion mechanism than polymer fragments. The diffusion rate of the fragments up to a size of octamers was found to be size-dependent and reasonably well approximated by a 1/N behavior, in line with the Rouse model. KW - Small-angle X-ray scattering KW - SAXS KW - Nanostructure KW - PLGA PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621250 DO - https://doi.org/10.1016/j.polymdegradstab.2024.111119 VL - 232 SP - 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-62125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, Z. A1 - Klein, P. A1 - Theiler, Geraldine A1 - Hübner, Wolfgang T1 - Sliding performance of polymer composites in liquid hydrogen and liquid nitrogen N2 - Outstanding features favour the application of polymers and polymer composites in low-temperature technology. The booming hydrogen technology is a challenge for these materials, which are considered as seals and bearings in cryogenic pumps. In the present study, three types of thermoplastics, i.e., polyetheretherketone (PEEK), polyetherimide (PEI) and polyamide 6,6 (PA6,6), and one epoxy were considered as matrix materials. Micron-sized fillers, i.e., short carbon fibres, graphite flakes, and PTFE powders, were incorporated into these polymers together with nano-sized TiO2 particles. Optimised compositions of each matrix were selected from our previous works at room temperature in order to be studied at very low temperature conditions. In particular, frictional tests were carried out with polymer composite pins against polished steel surfaces under constant load over a certain distance in liquid hydrogen and liquid nitrogen. Afterwards, worn surfaces were analysed by using scanning electron microscopy (SEM). It was found out that the tribological properties in liquid hydrogen are dominated by the matrix materials, in particular thermoplastics perform generally slightly better than thermosetting resins. PY - 2004 SN - 0957-4530 SN - 1573-4838 VL - 39 IS - 9 SP - 2989 EP - 2995 PB - Springer CY - Norwell, Mass. AN - OPUS4-12664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ammerman, D. J. A1 - Bignell, J. L. A1 - Bjorkman, G. S. A1 - Breach, M. R. A1 - Broz, V. A. A1 - Jordan, J. A1 - Kuehner, S. A1 - Molitoris, D. P. A1 - Reinhardt, W. A1 - Rigato, A. B. A1 - Rosvall, E. S. A1 - Sakalaukus Jr., P. J. A1 - Shih, P. Y.-K. A1 - Siromani, D. A1 - Snow, S. D. A1 - Tso, C.-F. A1 - Yaksh, M. C. A1 - Zencker, Uwe A1 - Zhang, X. T1 - Guidance document - Use of explicit finite element analysis for the evaluation of radioactive material transport packages and storge casks in energy-limited impact events N2 - The purpose of this document is to provide guidance for developing quality finite element models to ensure, with reasonable certainty, that the model produces accurate results for comparison with the strain-based or stress-based acceptance criteria of Section III, Division 3 of the ASME Boiler and Pressure Vessel Code, but could be applicable to other Sections of the Code or other codes. Models developed following the guidance provided in this document meet the definition of a "Quality Model," as described in Paragraph EE 1240 of the Nonmandatory Appendix EE (Strain-Based Acceptance Criteria Definitions and Background Information). It cannot be emphasized enough, however, that the guidance supplied here does not constitute requirements. Rather, the intent of the guidance is to give practical direction to analysts (i.e., this is not a set of regulatory requirements). This guidance document is an "evolving" document. It will undergo revision as computing capability and FEA techniques progress, and as example problems are developed. KW - Computational modeling KW - Explicit dynamics PY - 2025 SN - 978-0-7918-7749-4 VL - NTB-6 SP - 1 EP - 153 PB - Americal Society of Mechanical Engineers (ASME) CY - New York, NY ET - 2025 AN - OPUS4-65759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trimpin, S. A1 - Inutan, E. A1 - Karki, S. A1 - Elia, E. A1 - Zhang, W. A1 - Weidner, Steffen A1 - Marshall, D. A1 - Hoang, K. A1 - Lee, C. A1 - Davis, E. A1 - Smith, V. A1 - Meher, A. A1 - Cornejo, M. A1 - Auner, G. A1 - McEwen, C. T1 - Fundamental studies of new ionization technologies and insights from IMS-MS N2 - Exceptional ion mobility spectrometry mass spectrometry (IMS-MS) developments by von Helden, Jarrold, and Clemmer provided technology that gives a view of chemical/biological compositions previously not achievable. The ionization method of choice used with IMS-MS has been electrospray ionization (ESI). In this Special issue contribution, we focus on fundamentals of heretofore unprecedented means for transferring volatile and nonvolatile compounds into gas-phase ions singly and multiply charged. These newer ionization processes frequently lead to different selectivity relative to ESI and, together with IMS-MS, may provide a more comprehensive view of chemical compositions directly from their original Environment such as surfaces, e.g., tissue. Similarities of results using solvent- and matrix-assisted ionization are highlighted, as are differences between ESI and the inlet ionization methods, especially with mixtures such as bacterial extracts. Selectivity using different matrices is discussed, as are results which add to our fundamental knowledge of inlet ionization as well as pose additional avenues for inquiry. IMS-MS provides an opportunity for comparison studies relative to ESI and will prove valuable using the new ionization technologies for direct analyses. Our hypothesis is that some ESI-IMS-MS applications will be replaced by the new ionization processes and by understanding mechanistic aspects to aid enhanced source and method developments this will be hastened. KW - Inlet ionization KW - Vacuum ionization KW - Matrices KW - Fundamentals KW - Ion mobility PY - 2019 DO - https://doi.org/10.1007/s13361-019-02194-7 SN - 1044-0305 SN - 1879-1123 VL - 30 IS - 6 SP - 1133 EP - 1147 PB - Springer AN - OPUS4-48011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -