TY - CONF A1 - Hildebrandt, Jana T1 - Aqueous dispersions of polypropylene: towards referencematerials for nanoplastics characterization N2 - Plastic pollution in the environment is a rising concern for the health of our planet. The plastic litter that pollutes our environment leads to microplastic particles. They can be found (nearly) everywhere. The processes that lead to microplastic can also form nanoplastic particles, which have a size below 1 µm. Because of the small size they can penetrate tissue more easily. Only few risk assessment studies of nanoplastics were carried out so far. Using polystyrene (PS) nanoparticles to test effects on organisms is easy because it is commercially available. However, this falls a little short, as the polyolefins i.e., polypropylene (PP) and polyethylene (PE), are produced in a larger proportion than PS. Moreover, these plastics are mainly used for disposable products, which means that they also account for a large proportion of plastic waste. Therefore, the percentage of polyolefins in environmental nanoplastic is presumably high. It is important to test the toxicological effects also with nanoplastics made of PP and PE to have more realistic results. Herein, we present an easy and repeatable method to prepare an aqueous dispersion of polypropylene nanoplastics (nano-PP). They are stabilized electrostatically, resulting in a strongly negative zeta potential of -43 mV (± 2 mV) and making no surfactant necessary to keep the dispersion stable. The size and the size distribution were determined via Dynamic Light Scattering (DLS) and gives a hydrodynamic diameter of 180.5 nm (± 5.8 nm) and a PDI of 0.084 (± 0.023). Finally, ca. 480 bottles of the dispersion with a volume of 10 mL each were prepared to serve as a potential reference material for further testing of detection methods or risk assessments. T2 - International Conference on Microplastic Pollution in the Mediterranean Sea CY - Neapel, Italy DA - 25.09.2022 KW - Nanoplastic PY - 2022 AN - OPUS4-55963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hildebrandt, Jana T1 - Aqueous Dispersions of polypropylene as possible reference material for nanoplastics N2 - Plastic debris in micron and nanometer scale pollutes the nature all over the world. The potential dangers of these pollutants remain unpredictable. While risk assessment studies on microplastics are already popular, nanoplastic has not yet reached the same focus of investigation. The reason for this difference is simple: There is a "methodological gap" in the analytics of plastic particles with a diameter smaller than 1 µm. Submicron and nanoplastic particles are currently not detectable in environmental matrices. Therefore, it is important for researchers to have a well-characterized nanoplastic material, that serves as a reference for nanoplastics found in nature. Our aim was to synthesize nanoplastics made from the most common used plastics such as polypropylene (PP). We found an easy way to form nanoparticles consisting of PP (nano-PP), adapting and improving the method presented for polystyrene (PS). Nano-PP was formed via a top-down method where the polymer was dispersed to acetone and then transferred to water. No additional surfactant is needed to obtain a dispersion which is stable for more than 35 weeks. The success of forming nanoplastics and their size was detected via scattering methods, predominantly dynamic light scattering (DLS). The chemical analysis of the nanoplastics was performed via Fourier Transform Infrared spectroscopy. To examine the good stability of the nanoparticles, zeta potential measurements were performed, which revealed zeta potentials of -30 to -40 mV. T2 - European Polymer Congress 2022 CY - Prag, Czechia DA - 26.06.2022 KW - Nanoplastic PY - 2022 AN - OPUS4-55960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kling e Silva, Lucas T1 - AQSD - Magnetic characterization of steels AlSi A 366, AlSi S 235 and AlSi 304 using bitter technic (ferrofluid) T2 - XIV Brazilian Materials Research Society meeting CY - Rio de Janeiro, Brazil DA - 2015-09-27 PY - 2015 AN - OPUS4-34152 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Molnarne, Maria T1 - Approximation of the explosion limit curves around the apex for different mixtures containing flammable/inert/oxidising gases (ROBBANÁSI HATÁRGÖRBÉK FORDULÓPONT KÖRÜLI KÖZELÍTÉSE KÜLÖNBÖZÖ TIPUSÚ ÉGHETÖGÁZ-INERGÁZ-OXIDÁTOR ELEGYEKNÉL) T2 - Müszaki Kémiai Napok '05 (Technische Chemie Tagung '05) CY - Veszprém, Hungary DA - 2005-04-26 PY - 2005 AN - OPUS4-7665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madia, Mauro T1 - Approximation of the crack driving force for cracks at notches under static and cyclic loading N2 - The work deals with the efficient calculation of the elastic-plastic crack driving force (J-integral for monotonic loading andΔJ-integral under cyclic loading) for short cracks at notches as essential parameter for the reliable static and fatigue assessment of notched structures. The J- or ΔJ-integral is calculated based on analytical solutions for stress intensity factors, estimated by means of well-known weight function solutions in the case of cracks under power-law stress distributions. A plasticity-correction function is applied to the stress intensity factors to obtain the final expression of the crack driving force. The comparison between analytical solutions and finite element calculations in case of cracks at the weld toe in welded joints shows good agreement. T2 - 2nd International Conference on Structural Integrity CY - Funchal, Madeira, Portugal DA - 04.09.2017 KW - Structural integrity KW - Fracture mechanics KW - Crack driving force KW - Notches PY - 2017 AN - OPUS4-42558 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Cheng-Chieh T1 - Approximate model for geometrical complex structures N2 - Many engineering structures are made of composite materials or metal foam. To simulate the deformational behaviour of these structures often requires a high number of discretisation elements. This in turn yields a very large system of linear equations that are extremely time and memory consuming or practically impossible to solve. It is therefore desirable to find an approach to overcome this obstacle. T2 - 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Inverse analysis KW - Finite element method KW - Least-squares adjustment PY - 2016 AN - OPUS4-37523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Cheng-Chieh T1 - Approximate model for geometrical complex structures N2 - Many engineering structures are made of composite materials or metal foam. To simulate the deformational behaviour of these structures often requires a high number of discretisation elements. This in turn yields a very large system of linear equations that are extremely time and memory consuming or practically impossible to solve. It is therefore desirable to find an approach to overcome this obstacle. T2 - 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Inverse analysis KW - Finite element method KW - Least-squares adjustment PY - 2016 AN - OPUS4-37524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fomine, Pavel T1 - Approximale model of chemical equilibrium in heterogeneous gas-particles mixtures T2 - 4th International Seminar on Fire and Explosion Hazards CY - Londonderry, Northern Ireland DA - 2003-09-08 PY - 2003 AN - OPUS4-3927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blümel, Peter T1 - Approval of packagings with alternative HDPE grades based on comparative testing T2 - The 15th IAPRI World Conference on Packaging CY - Tokyo, Japan DA - 2006-10-04 PY - 2006 AN - OPUS4-14260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wöhlecke, Andreas T1 - Approval of geosynthetics, polymers and leak detection systems for German landfills N2 - Geokunststoffe spielen sowohl im internationalen als auch im deutschen Deponiebau eine Schlüsselrolle. Seit dem Erscheinen der Deponieverordnung (DepV) im Jahre 2009 bedürfen Geokunststoffe, Polymere und Dichtungskontrollsysteme einer Zulassung durch die BAM, wenn diese in deutschen Deponieabdichtungssystemen eingesetzt werden sollen. Die DepV stellt dabei allgemeine Anforderungen an die Geokunststoffe und den Zulassungsprozess für die Produkte auf. Geokunststoffe müssen danach ihre Funktion unter allen zu erwartenden äußeren und inneren Einflüssen über einen Zeitraum von mindestens 100 Jahren erfüllen. Dichtungskontrollsysteme müssen ihre Funktion über mindestens 30 Jahre erfüllen. Die Anforderungen der DepV werden durch die Zulassungsrichtlinien der BAM in konkrete technische Anforderungen für die Produkte aber auch für das Qualitätsmanagement und den Einbau etc. überführt. Bei der Erarbeitung der Zulassungsrichtlinien wird die BAM durch einen Fachbeirat, der sich aus Experten aus allen relevanten Bereichen zusammensetzt, beraten. Der Vorsitz des Fachbeirats liegt beim UBA. Es soll eine kurze Übersicht über die Produkte und die wichtigsten Anforderungen gegeben werden. Zudem soll erläutert werden, durch welche Maßnahmen in der Produktion und auf der Deponiebaustelle eine gleichbleibende Qualität der Produkte gewährleistet wird. T2 - COLLOQUIUM DEPARTMENT 4 „MATERIALS AND THE ENVIRONMENT” CY - Berlin, Germany DA - 14.11.2018 KW - Deponien KW - Geokunststoffe KW - Polymere KW - Dichtungskontrollsysteme PY - 2018 AN - OPUS4-46659 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -