TY - CONF A1 - Fortini, Renata A1 - Sturm, Heinz A1 - Meyer-Plath, A. A1 - Kehren, D. T1 - Development of a method for measuring the flexural rigidity of nanofibres N2 - Toxicological studies have shown that some types of carbon nanotubes may provoke asbestos-like effects including chronic inflammation and lung cancer. Inhaled carbon nanotubes may reach the deep lung tissue. Alveolar macrophages are responsible to remove such foreign objects from the alveoli in a process called phagocytosis. If a macrophage fails to uptake a nanotube completely, cell lesions may give rise to inflammation. It is currently assumed that short, flexible and long as well as granularly agglomerated (tangled) nanofibres are clearable by macrophages, whereas biodurable long and rigid nanotubes may persist in lung tissue. The flexural rigidity of nanofibres is therefore believed to be an important material property that governs fibre toxicity and needs to be investigated. The present work aims at determining the rigidity of nanofibres by detecting their resonance frequencies using a Dynamic Scanning Electron Microscope (DySEM) setup. By depositing and fixing a nanofibre to an oscillating support, it can be excited to vibrations and treated as a cantilevered beam. This way, its elastic modulus can be determined via Euler-Bernoulli’s beam theory. Multi-walled carbon nanotubes (MWCNTs) were deposited on high frequency piezoelectric quartz crystals mounted on a scanning electron microscope (SEM) holder. When introduced into the SEM chamber and connected to a frequency-sweeping waveform generator, the quartz crystal actuates the deposited fibre. A lock-in amplified processes the secondary electron detector signal resulting from the electron beam modulated by the vibrating nanofibre. Whenever a fibre resonance is detected, the SEM image of the fibre is stored to identify the fibre oscillation mode. The found resonance frequencies and modes allow determining the elastic modulus accordingly. Since the frequency spacing of resonances is predicted by Euler-Bernoulli, the mode number can be identified and elastic modulus values be averaged. A significant number of individual MWCNTs were classified according to their level of rigidity. The applicability and reliability of the method will be discussed. T2 - Microscopy Conference CY - Berlin, Germany DA - 01.09.2019 KW - Carbon nanotubes KW - Rigidity KW - Resonance frequency KW - Nanofibers KW - Bending modulus PY - 2019 AN - OPUS4-49198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fortini, Renata A1 - Sturm, Heinz A1 - Meyer-Plath, Asmus A1 - Kehren, Dominic T1 - Development of a method for measuring the flexural rigidity of nanofibres N2 - Toxicological studies have shown that some types of carbon nanotubes may provoke asbestos-like effects including chronic inflammation and lung cancer. Inhaled carbon nanotubes may reach the deep lung tissue. Alveolar macrophages are responsible to remove such foreign objects from the alveoli in a process called phagocytosis. If a macrophage fails to uptake a nanotube completely, cell lesions may give rise to inflammation. It is currently assumed that short, flexible and long as well as granularly agglomerated (tangled) nanofibres are clearable by macrophages, whereas biodurable long and rigid nanotubes may persist in lung tissue. The flexural rigidity of nanofibres is therefore believed to be an important material property that governs fibre toxicity and needs to be investigated. The present work aims at determining the rigidity of nanofibres by detecting their resonance frequencies using a Dynamic Scanning Electron Microscope (DySEM) setup. By depositing and fixing a nanofibre to an oscillating support, it can be excited to vibrations and treated as a cantilevered beam. This way, its elastic modulus can be determined via Euler-Bernoulli’s beam theory. Multi-walled carbon nanotubes (MWCNTs) were deposited on high frequency piezoelectric quartz crystals mounted on a scanning electron microscope (SEM) holder. When introduced into the SEM chamber and connected to a frequency-sweeping waveform generator, the quartz crystal actuates the deposited fibre. A lock-in amplified processes the secondary electron detector signal resulting from the electron beam modulated by the vibrating nanofibre. Whenever a fibre resonance is detected, the SEM image of the fibre is stored to identify the fibre oscillation mode. The found resonance frequencies and modes allow determining the elastic modulus accordingly. Since the frequency spacing of resonances is predicted by Euler-Bernoulli, the mode number can be identified and elastic modulus values be averaged. A significant number of individual MWCNTs were classified according to their level of rigidity. The applicability and reliability of the method will be discussed. T2 - EUROMAT CY - Stockholm, Sweden DA - 01.09.2019 KW - Carbon nanotubes KW - Rigidity KW - Resonance frequency KW - Nanofibers KW - Bending modulus PY - 2019 AN - OPUS4-49197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fortini, Renata A1 - Sturm, Heinz A1 - Meyer-Plath, Asmus A1 - Kehren, Dominic T1 - Development of a method for measuring the flexural rigidity of nanofibers N2 - Toxicological studies have shown that some types of carbon nanotubes may provoke asbestos-like effects including chronic inflammation and lung cancer. Inhaled carbon nanotubes may reach the deep lung tissue. Alveolar macrophages are responsible to remove such foreign objects from the alveoli in a process called phagocytosis. If a macrophage fails to uptake a nanotube completely, cell lesions give rise to inflammation. It is currently assumed that short, long and flexible, and granularly agglomerated (tangled) nanofibres are clearable by macrophages, whereas biodurable long and rigid nanotubes persist in the lung tissue. The flexural rigidity of nanofibres is therefore believed to an important material property that governs fibre toxicity and needs to be investigated. The present work aims at determining the rigidity of nanofibres by detecting their resonance frequencies using a Dynamic Scanning Electron Microscope (DySEM) setup. By depositing and fixing a nanofibre to an oscillating support, it can be excited to vibrations and treated as a cantilevered beam. This way, its elastic modulus can be determined via Euler-Bernoulli’s beam theory. Multi-walled carbon nanotubes (MWCNTs) were deposited on high frequency piezoelectric quartz crystals mounted on a scanning electron microscope (SEM) holder. When introduced into the SEM chamber and connected to a frequency-sweeping waveform generator, the quartz crystal actuates the deposited fibre. A lock-in amplified processes the secondary electron detector signal resulting from the electron beam modulated by the vibrating nanofibre. Whenever a fibre resonance is detected, the SEM image of the fibre is stored to identify the fibre oscillation mode. The found resonance frequencies and modes allow determining the elastic modulus according. Since the frequency spacing of resonances is predicted by Euler-Bernoulli, the mode number can be checked and elastic modulus values be averaged. A significant number of MWCNTs have been classified according to their level of rigidity. The applicability and reliability of the method will be discussed. T2 - International Conference on Multifunctional, Hybrid and Nanomaterials CY - Sitges, Spain DA - 11.03.2019 KW - Carbon nanotubes KW - Rigidity KW - Resonance KW - Nanofibers KW - Bending modulus PY - 2019 AN - OPUS4-49196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghasem Zadeh Khorasani, Media A1 - Silbernagel, Dorothee A1 - Sturm, Heinz T1 - Long range influence of boehmite nanoparticles on the nanomechanics of epoxy matrix used in carbon-fiber composites N2 - Boehmite nanoparticles (AlOOH) were recently found to improve properties such as crack resistance, shrinkage and compressive strength in epoxy composites. Concentration and surface modification of boehmite nanoparticles are key factors for abovementioned enhancements. To understand the underlying mechanisms, more detailed research of micro- and nanoscopic mechanical properties is required. The presented study aims to investigate the influence of concentration and surface modification of boehmite on the stiffness of the bulk epoxy by means of AFM-based approaches: Force-Distance curves (FDC) on the sub- microscale and Intermodulation AFM and amplitude-dependent force spectroscopy (ADFS) on the nanoscale. For this purpose, stiffness-maps of epoxy filled with boehmite, with and without surface modification (HAc-boehmite) were obtained by FDC. These measurements showed a slight increase in overall stiffness of composite with increasing the nanoparticle content. The stiffening effect was observed to be intensified with HAc-boehmite. Since the lateral resolution of FDC is not high enough to distinguish nanoparticles, this effect was assumed to be due to the inevitable inclusion of nanoparticles in the measurement. By using Intermodulation-AFM, yielding ADFS stiffness maps with the resolution of <10 nm, we were able to calculate the average stiffness of bulk epoxy without the interference of nanoparticles. It was expected that the stiffness of regions faraway from particles would be equal to neat epoxy. In contrast, the results showed a drastic increase in stiffness of epoxy with increasing boehmite concentration (0, 1, 2.5, and 15%) especially in case of introducing 15wt% HAc-boehmite. Another important observation was formation of a spatial structure with non-homogenous stiffness distribution in bulk epoxy with HAc-boehmite. The underlying mechanisms of described observations are not fully understood yet. One hypothesis is the local increase in crosslinking density which we aim to investigate in our further studies by combining Dynamic Mechanical Thermal Analysis (DMTA) and Intermodulation-AFM. T2 - Frontiers in Polymer Science CY - Seville, Spain DA - 17.05.2017 KW - AFM KW - Boehmite KW - Epoxy nanocomposite PY - 2017 AN - OPUS4-50688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Towards Reproducible Analysis Workflows for Reliable Structural and Chemical Composition of Industrial Graphene N2 - The scientific and technological interest in graphene has been growing more and more in the late years due to its outstanding properties and diverse promising applications. However, graphene implementation into the industrial market is still limited and many challenges are yet to be addressed before this material can become suitable for the large-scale production. One of the most crucial challenge to overcome is to develop reliable and reproducible ways to characterize the material properties which can heavily affect the product performance. In our study the chemical composition of nine different samples of industrial graphene, graphene oxide and functionalized graphene were investigated. The samples were analysed both in form of powder and pellets. A comparative characterisation of the chemical composition was performed through X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X-ray Spectroscopy (EDX). XPS depth resolution is in the order of 10 nm, while for EDX the analysis was performed at two different energy levels, i.e. 5 keV and 15 keV, and thus varying the analysis depth from 200 nm to 2000 nm. The XPS measurement area is 300x700 µm² while the EDX measurement was performed by analysing a grid of 25 locations (5x5) of 150 x 150 ?m2 area, covering the whole pellet surface of 5 mm diameter and then calculating the mean of the elemental concentration. The results of the elemental concentration values from XPS and EDX analyses show a good agreement for all the elements presents in the samples, despite the different spatial resolutions of the two techniques. Therefore, the samples appear homogeneous both in the lateral and vertical directions. The results relative to powder and pellets samples do not differ in a significant way except for a slight increase in the carbon content regarding the pellet samples, probably due to a minor contamination effect introduced through pressing. Nevertheless, pellets samples appear to be quite representative for the material while being much more convenient in terms of handling and safety compared to nano-powders and providing a regular flat surface for EDX analysis. Finally, this approach correlating XPS and EDS represents a simple, fast and reliable way for characterizing the chemical composition and the homogeneity of industrial graphene. This study is part of the project Standardisation of structural and chemical properties of graphene (ISO-G-SCoPe) which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union?s Horizon 2020 research and innovation programme under Grant agreement No. 19NRM04. T2 - SALSA Make and Measure... and Machines CY - Online meeting DA - 16.09.2021 KW - Graphene KW - XPS KW - EDX KW - Graphene functionalisation PY - 2021 UR - https://fakultaeten.hu-berlin.de/en/mnf/forschung_internationales/grs/salsa/SALSA_MM AN - OPUS4-53463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chemello, Giovanni A1 - Radnik, Jörg A1 - Hodoroaba, Vasile-Dan T1 - Correlative analysis through XPS and EDX measurements for accurate chemical composition of industrial Graphene N2 - The scientific and technological interest in graphene has been growing more and more in the late years due to its outstanding properties and diverse promising applications. However, graphene implementation into the industrial market is still limited and many challenges are yet to be addressed before this material can become suitable for the large-scale production. One of the most crucial challenge to overcome is to develop reliable and reproducible ways to characterize the material properties which can heavily affect the product performance. In our study the chemical composition of nine different samples of industrial graphene, graphene oxide and functionalized graphene were investigated. The samples were analysed both in form of powder and pellets. A comparative characterisation of the chemical composition was performed through X-ray Photoelectron Spectroscopy (XPS) and Energy Dispersive X-ray Spectroscopy (EDX). XPS depth resolution is in the order of 10 nm, while for EDX the analysis was performed at two different energy levels, i.e. 5 keV and 15 keV, and thus varying the analysis depth from 200 nm to 2000 nm. The XPS measurement area is 300x700 µm² while the EDX measurement was performed by analysing a grid of 25 locations (5x5) of 150 x 150 ?m2 area, covering the whole pellet surface of 5 mm diameter and then calculating the mean of the elemental concentration. The results of the elemental concentration values from XPS and EDX analyses show a good agreement for all the elements presents in the samples, despite the different spatial resolutions of the two techniques. Therefore, the samples appear homogeneous both in the lateral and vertical directions. The results relative to powder and pellets samples do not differ in a significant way except for a slight increase in the carbon content regarding the pellet samples, probably due to a minor contamination effect introduced through pressing. Nevertheless, pellets samples appear to be quite representative for the material while being much more convenient in terms of handling and safety compared to nano-powders and providing a regular flat surface for EDX analysis. Finally, this approach correlating XPS and EDS represents a simple, fast and reliable way for characterizing the chemical composition and the homogeneity of industrial graphene. This study is part of the project ?Standardisation of structural and chemical properties of graphene? (ISO-G-SCoPe) which has received funding from the EMPIR programme co-financed by the Participating States and from the European Union?s Horizon 2020 research and innovation programme under Grant agreement No. 19NRM04. T2 - 2021 Fall Meeting of the European Materials Research Society (E-MRS) CY - Online meeting DA - 20.9.2021 KW - Graphene KW - XPS KW - EDS KW - Standardisation KW - Graphene functionalization PY - 2021 UR - https://www.european-mrs.com/meetings/2021-fall-meeting AN - OPUS4-53462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Zutta Villate, J. M. T1 - BP150: Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement by Monte-Carlo based particle scattering Simulations N2 - Dose enhancement by gold nanoparticles (AuNP) increases the biological effectiveness of radiation damage in biomolecules and tissue. To apply them effectively during cancer therapy their influence on the locally delivered dose has to be determined. Hereby, the AuNP locations strongly influence the energy deposit in the nucleus, mitochondria, membrane and the cytosol of the targeted cells. In this work, two newly developed continuous and discrete-geometric models for simulations of AuNP in cells are presented. We apply the presented models in Monte-Carlo particle scattering simulations to characterize the energy deposit in cell organelles by radioactive 198AuNP. They emit beta and gamma rays and are therefore considered for applications with solid tumors. Differences in local dose enhancement between randomly distributed and nucleus targeted nanoparticles are compared. Hereby nucleus targeted nanoparticels showed a strong local dose enhancement in the radio sensitive nucleus. T2 - DPG Frühjahrstagung CY - Dresden, Germany DA - 26.03.2023 KW - AuNP KW - Beta decay KW - Brachytherapy KW - Cancer treatment KW - Clustered nanoparticles KW - DNA KW - DNA damage KW - Dosimetry KW - Energy deposit KW - Geant4 KW - Geant4-DNA KW - Gold Nanoparticles KW - LEE KW - Livermore model KW - Low energy electrons KW - MCS KW - Microdosimetry KW - Monte-Carlo simulation KW - NP KW - OH radical KW - Penelope model KW - Radiation damage KW - Radiation therapy KW - Radiationtherapy KW - Radioactive decay KW - Radiolysis KW - Radiotherapy KW - Simulation KW - TOPAS KW - TOPAS-nbio KW - Beta particle KW - Particle scattering KW - Protein KW - Proteins PY - 2023 AN - OPUS4-57253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement by Monte-Carlo based particle scattering Simulations N2 - Dose enhancement by gold nanoparticles (AuNP) increases the biological effectiveness of radiation damage in biomolecules and tissue. To apply them effectively during cancer therapy their influence on the locally delivered dose has to be determined.[1] Hereby, the AuNP locations strongly influence the energy deposit in the nucleus, mitochondria, membrane and the cytosol of the targeted cells. To estimate these effects, particle scattering simulations are applied. In general, different approaches for modeling the AuNP and their distribution within the cell are possible. In this work, two newly developed continuous and discrete-geometric models for simulations of AuNP in cells are presented. [2] These models are applicable to simulations of internal emitters and external radiation sources. Most of the current studies on AuNP focus on external beam therapy. In contrast, we apply the presented models in Monte-Carlo particle scattering simulations to characterize the energy deposit in cell organelles by radioactive 198AuNP. They emit beta and gamma rays and are therefore considered for applications with solid tumors. Differences in local dose enhancement between randomly distributed and nucleus targeted nanoparticles are compared. Hereby nucleus targeted nanoparticels showed a strong local dose enhancement in the radio sensitive nucleus. These results are the foundation for ongoing experimental work which aims to obtain a mechanistic understanding of cell death induced by radioactive 198Au. T2 - #RSCposter 2023 CY - Online meeting DA - 28.02.2023 KW - AuNP KW - Beta decay KW - Brachytherapy KW - Cancer treatment KW - Clustered nanoparticles KW - DNA KW - DNA damage KW - Dosimetry KW - Energy deposit KW - Geant4 KW - Geant4-DNA KW - Gold Nanoparticles KW - LEE KW - Livermore model KW - Low energy electrons KW - MCS KW - Microdosimetry KW - Monte-Carlo simulation KW - NP KW - OH radical KW - Penelope model KW - Radiation damage KW - Radiation therapy KW - Radiationtherapy KW - Radiotherapy KW - Radioactive decay KW - Radiolysis KW - Simulation KW - TOPAS KW - TOPAS-nbio KW - beta particle KW - particle scattering PY - 2023 AN - OPUS4-57060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Temperature in micromagnetism: Cell size and scaling effects of the stochastic Landau-Lifshitz equation N2 - The movement of the macroscopic magnetic moment in ferromagnetic systems can be described by the Landau-Lifshitz (LL) or Landau-Lifshitz-Gilbert (LLG) equation. These equations are strictly valid only at absolute zero temperature. To include temperature effects a stochastic version of the LL or LLG equation for a spin density of one per unit cell can be used instead. To apply the stochastic LL to micromagnetic simulations, where the spin density per unit cell is generally higher, a conversion regarding simulation cell size and temperature has to be established. Based on energetic considerations, a conversion for ferromagnetic bulk and thin film systems is proposed. The conversion is tested in micromagnetic simulations which are performed with the Object Oriented Micromagnetic Framework (OOMMF). The Curie temperatures of bulk Nickel, Cobalt and Iron systems as well as Nickel thin-film systems with thicknesses between 6.3 mono layer (ML) and 31ML are determined from micromagnetic simulations. The results show a good agreement with experimentally determined Curie temperatures of bulk and thin film systems when temperature scaling is performed according to the presented model. T2 - #RSCposter 2023 CY - Online meeting DA - 28.02.2023 KW - Exchange interaction KW - Ferromagnetism KW - LLG KW - Landau Lifshitz equation KW - Magnetic moment KW - Magnetic nanoparticles KW - Micromagnetism KW - OOMMF KW - Object oriented micromagnetic framework KW - Stochastic Landau Lifshitz Gilbert equation KW - Temperature scaling PY - 2023 AN - OPUS4-57062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon J. A1 - Breese, Philipp P. A1 - Oster, Simon A1 - Becker, Tina T1 - SAMMIE: Eigenbau-Anlage für Metall-AM zur Sensorentwicklung und Qualifizierung N2 - Im additiven Fertigungsprozess Laser-Pulverbettschweißen wird Metallpulver lagenweise mittels eines Lasers aufgeschmolzen, um Bauteile zu generieren. Hierbei werden die Eigenschaften der Bauteile zu einem großen Teil durch die im Verlauf des Prozesses vorliegenden Temperaturen bestimmt. Dies beinhaltet unter anderem Materialeigenschaften wie Mikrostruktur, Härte, thermische und elektrische Leitfähigkeiten sowie die Ausbildung von Defekten wie z.B. Anbindungsfehler, Keyhole-Porosität (Gaseinschlüsse) oder auch die Ausbildung von Rissen. Zur Überwachung bzw. Vorhersage dieser Eigenschaften sowie zum Abgleich von Simulationen ist eine orts- und zeitaufgelöste Messung der Temperaturverteilung im Prozess daher von herausragender Bedeutung. In der Industrie kommen optische Verfahren, die auf der Messung der thermischen Strahlung basieren, regelmäßig zum Einsatz. Allerdings dienen diese bislang nur der statistischen Auswertung und der Identifikation von Abweichungen vom Normalprozess. Der quantitativen Auswertung zur Temperaturbestimmung stehen aktuell noch eine Vielzahl von Herausforderungen entgegen. Einerseits stellt der Prozess an sich hohe Anforderungen an die Datenerfassung und -auswertung: der Emissionsgrad verändert sich dynamisch im Prozess und lokale Schmauchbildung sorgt für potenzielle Absorption oder Streuung der thermischen Strahlung oder auch des Fertigungslasers. Weiterhin stellt der hochdynamische Prozess hohe Anforderungen an Orts- und Zeitauflösung der eingesetzten Sensorik (z.B. Kameratechnik). Andererseits erschweren an üblichen kommerziell erhältlichen Fertigungsanlagen praktische Hindernisse wie eine eingeschränkte optische Zugänglichkeit und der fehlende Zugriff auf die Anlagensteuerung sowie fehlende Möglichkeiten der Synchronisation der Messtechnik mit dem Prozess eine eingehende Untersuchung dieser Effekte. Um letztere Hindernisse zu umgehen, wurde an der BAM die Forschungsanlage SAMMIE (sensor-based additive manufacturing machine) entwickelt. Einerseits bietet das System alle Möglichkeiten, die auch übliche kommerzielle Systeme bieten. Dies beinhaltet die Fertigung ganzer Bauteile (maximale Größe ca. 65mm x 45 mm x 30 mm) und den Einsatz einer Inertgasatmosphäre inkl. gefiltertem Schutzgasstrom. Andererseits bietet es aber auch einen besonders kompakten Bauraum, um die Sensorik möglichst nah an den Prozess führen zu können, sechs optische Fenster zur Prozessbeobachtung aus unterschiedlichen Winkeln und die Möglichkeit der Prozessbeobachtung koaxial zum Fertigungslaser. Des Weiteren besteht eine einfache Austauschbarkeit aller Fenster, Spiegel und Strahlteiler, um den gesamten optischen Pfad der aktuellen Messaufgabe flexibel anzupassen. Die komplette Anlagensteuerung ist eine Eigenentwicklung und bietet daher auch völlige Anpassbarkeit. Eine synchrone und frei konfigurierbare Triggerung diverser Sensoriken und synchrone Datenerfassung bieten maximale Kontrolle über die Sensorsteuerung. Dieser Beitrag gibt einen Überblick über die Fertigungsanlage SAMMIE. Wissenschaftliche Ergebnisse sowie laufende Arbeiten an der Anlage werden in weiteren Beiträgen vorgestellt. T2 - Temperatur 2024 CY - Berlin, Germany DA - 05.06.2024 KW - PBF-LB/M KW - In situ monitoring KW - Anlage KW - Additive Fertigung KW - Prozessüberwachung KW - Additive Manufacturing PY - 2024 AN - OPUS4-60234 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -