TY - CONF A1 - Krüger, Simone A1 - Despinasse, Marie-Claire A1 - Stahn, Sebastian A1 - Raspe, Tina A1 - Nörthemann, K. A1 - Moritz, W. T1 - Freisetzung toxischer Gase bei der Verwendung von Grillgeräten in geschlossenen Räumen und deren frühzeitige Detektion N2 - Durch die Verwendung von Grillgeräten in geschlossenen Räumen, wie Gartenlauben, Wohnungen oder Garagen kam es in den vergangenen Jahren zu einer Vielzahl von Unfällen mit schweren Vergiftungen und Todesfällen. Seit 2008 scheint das Auftreten von Kohlenmonoxid (CO) Intoxikationen innerhalb Deutschland wieder zu zunehmen. Die Hauptursachen sind dabei der unsachgemäße Gebrauch von Holzkohlegrills, schlecht gewartete Gasthermen und Kamine. Zum Schutz der Bevölkerung ist deshalb eine Aufklärung über mögliche Gefahren wichtig. Im Rahmen dieser Arbeit wurden diese Gefahren bewertet. Es wurden verschiedene Brandszenarien mit Grillgeräten, mit unterschiedlichen Grillkohlearten und –mengen in geschlossenen Räumen realisiert und die entsprechenden Konzentrations-Zeit-Verläufe ermittelt. Bei den Brandversuchen wurden zudem notwendige Eingabeparameter für numerische Simulationen ermittelt, um die Verwendung von Holzkohlegrills in geschlossenen Räumen zu simulieren. Die Auswirkungen für Menschen beim Grillen in geschlossenen Räumen wurden quantifiziert, indem die Eintrittszeitpunkte der Handlungsunfähigkeit und des Todes mittels Fractional Effective Dose (FED)-Konzept bestimmt wurden. Die Ergebnisse zeigen deutlich, dass eine frühzeitige Detektion der toxischen Gase zur Warnung von Personen dringend notwendig ist. In den durchgeführten Brandversuchen zeigte sich, dass die gebräuchlichen Rauchmelder auf Streulichtbasis keine rechtzeitige Warnung ermöglichen. Deshalb sind für solche Brandszenarien andere Branddetektoren erforderlich. Entsprechende Versuche mit CO-Brandmeldern zeigten, dass das freigesetzte CO beim Grillen in geschlossenen Räumen frühzeitig detektiert werden kann und Personen somit rechtzeitig gewarnt werden können. Zur frühzeitigen Erkennung von Schwelbränden wurde weiterhin ein neuer Wasserstoffdetektor getestet. Die Entstehung von Wasserstoff in einer sehr frühen Brandphase kann zur frühzeitigen Erkennung von Schwelbränden genutzt werden. Bei ersten Schwelbrandexperimenten mit Holzproben konnte Wasserstoff in einer geschlossenen Kammer (0,5 m3) nachgewiesen werden, noch bevor es zu einer erhöhten CO-Emission kam. Die Ergebnisse der Schwelbrandversuche werden vorgestellt und die Verwendbarkeit von CO- und Wasserstoff-Detektoren erörtert und diskutiert. T2 - 4. Magdeburger Brand- und Explosionsschutztag / 3. vfdb-Workshop Brandschutzforschung CY - Magdeburg, Germany DA - 26.03.2015 KW - Toxizität KW - FED KW - Brandmelder KW - Brandfrüherkennung KW - Rauchgase KW - Kohlenmonoxid KW - Grillen PY - 2015 SN - 978-3-00-048960-0 SP - 1 EP - 13 AN - OPUS4-33188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Friedrich, Jörg Florian A1 - Krüger, Simone T1 - Cured melamine systems as thick fire-retardant layers deposited by combination of plasma technology and dip-coating N2 - Melamine and melamine resins are widely used as fire-retardants for polymer building materials. Cured melamine systems are used in heat-sensitive items, such as furniture and window frames and sills. In this work, differently cured methylated poly(melamine-co-formaldehyde) (cmPMF) resins were used as fire-retardant coverage for poly(styrene) (PS) and poly(ethylene) (PE) building materials. Such polymer layers should have several tenths of micrometers thickness to produce sufficient fire retardancy. These thick layers were produced by dip-coating. To promote sufficient adhesion of such thick coating to the polyolefin substrates, also in the case of high temperatures occurring at fire exposure, the polymer substrates were firstly coated with a few hundred nanometer thick adhesion-promoting plasma polymer layer. Such thin plasma polymer layers were deposited by low-pressure plasma polymerization of allyl alcohol (ppAAl). It was assumed that the hydroxyl groups of ppAAl interact with the melamine resin; therefore, ppAAl was well suited as adhesion promoter for thick melamine resin coatings. Chemical structure and composition of polymer films were investigated using infrared-attenuated total reflectance and X-ray photoelectron spectroscopy (XPS). Peel strengths of coatings were measured. After peeling, the peeled polymer surfaces were also investigated using optical microscopy and XPS the layers for identification of the locus of peel front propagation. Thermal properties were analyzed using TGA (thermo-gravimetric analyses). Finally, the fire-retardant properties of such thick coated polymers were evaluated by exposure to flames. KW - Plasma polymerization KW - Dip-coating KW - Curing KW - Methylated poly(melamine-co-formaldehyde) KW - Polystyrene KW - Polyethylene KW - Flame retardancy KW - Polymer KW - Plasma KW - Melamine resin KW - Fire retardant PY - 2015 DO - https://doi.org/10.1080/01694243.2014.995911 SN - 0169-4243 SN - 1568-5616 VL - 29 IS - 9 SP - 807 EP - 820 PB - VNU Science Press CY - Utrecht AN - OPUS4-32795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Despinasse, Marie-Claire A1 - Krüger, Simone T1 - First developments of a new test to evaluate the fire behavior of photovoltaic modules on roofs N2 - A new test for photovoltaic (PV) modules exposed to an external fire source on roofs is proposed, and first results are presented. This is a simplification of the standards commonly in use for testing PV modules as roofing parts, roofing components or building components. Most of the tests required different fire scenarios and the use of burning brands such as wood cribs. In our study we proposed replacing wooden burning brands with a propane burner, the output of which is close to the one that can be observed in the burning of wooden cribs 500 g and 2 kg in size. The fire behavior was assessed by measuring smoke evolution, burning drips, flaming debris, and the time to burn-through of monocrystalline, polycrystalline and amorphous silicon panels. Two different configurations of the burner were tested, with the fire source on the top of the module or under the tilted module, respectively. The fire behavior of the modules was dependent on the burner output (16 to 46 kW), but also on the construction type of the panel (glass/glass or glass/plastic sheet) and on the position of the fire source (top or bottom). These preliminary tests for further development of the procedure yielded encouraging results for the evaluation of PV panels on roofs. KW - Fire test KW - Photovoltaics KW - Roofs KW - Temperature measurements KW - Fire behavior KW - Fire engineering KW - Burn-through PY - 2015 DO - https://doi.org/10.1016/j.firesaf.2014.11.011 SN - 0379-7112 VL - 71 SP - 49 EP - 57 PB - Elsevier Ltd. CY - Kidlington, Oxford AN - OPUS4-32160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Koter, Robert A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Pentzien, Simone A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg T1 - Tribological performance of femtosecond laser-induced periodic surface structures on titanium and a high toughness bearing steel N2 - Laser-induced periodic surface structures (LIPSS, ripples) were processed on steel (X30CrMoN15-1) and titanium (Ti) surfaces by irradiation in air with linear polarized femtosecond laser pulses with a pulse duration of 30 fs at 790 nm wavelength. For the processing of large LIPSS covered surface areas (5 mm × 5 mm), the laser fluence and the spatial spot overlap were optimized in a sample-scanning geometry. The laser-processed surfaces were characterized by optical microscopy (OM), white light interference microscopy (WLIM) and scanning electron microscopy (SEM). Spatial LIPSS periods between 450 and 600 nm were determined. The nanostructured surface regions were tribologically tested under reciprocal sliding conditions against a 10-mm diameter ball of hardened 100Cr6 steel. Paraffin oil and engine oil were used as lubricants for 1000 sliding cycles at 1 Hz with a normal load of 1.0 N. The corresponding wear tracks were analyzed by OM and SEM. In particular cases, the laser-generated nanostructures endured the tribological treatment. Simultaneously, a significant reduction of the friction coefficient and the wear was observed in the laser-irradiated (LIPSS-covered) areas when compared to the non-irradiated surface. The experiments reveal the potential benefit of laser surface structuring for tribological applications. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser processing KW - Tribology KW - Metals PY - 2015 DO - https://doi.org/10.1016/j.apsusc.2014.08.111 SN - 0169-4332 SN - 1873-5584 VL - 336 SP - 21 EP - 27 PB - North-Holland CY - Amsterdam AN - OPUS4-32861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Friedrich, Jörg Florian A1 - Krüger, Simone T1 - Adhesion promotion of thick fire-retardant melamine polymer dip-coatings at polyolefin surfaces by using plasma polymers N2 - Melamine and melamine resins are widely used as fire retardants for polymer materials used in pharmaceutical, plastic, textile, rubber, and construction industry. Melamine-based flame retardants act by blowing off intumescent layers, char formation, and emission of quenching ammonia gas and diluent molecular nitrogen. Special advantages are: low cost, low smoke density and toxicity, low corrosive activity, safe handling, and environmental friendliness. Methylated poly(melamine-co-formaldehyde) (mPMF) was used as thick (≥40 µm) fire-retardant coating for plasma pretreated polymers. A combined low-pressure plasma pretreatment consisting of oxygen plasma exposure followed by deposition of thin poly(allylamine) (ppAAm) and poly(allyl alcohol) (ppAAl) plasma polymers as adhesion promoters have improved the adhesion of thick mPMF coatings strongly. Chemical structure and composition of deposited polymer films were characterized by infrared-attenuated total reflectance and X-ray photoelectron spectroscopy (XPS). After peeling, the peeled layer surfaces were also investigated for identification of the locus of failure and their topography using optical microscopy and XPS. Often the adhesion promotion was so efficient that the peeling of coating was not possible. Thermal properties of plasma polymers and dip-coating films were analyzed by thermogravimetric analysis. Significant improvement of fire-retardant properties of coated polymers was confirmed by flame tests. KW - Adhesion KW - Thick melamine layers KW - Plasma polymerization KW - Dip-coating KW - Methylated poly(melamine-co-formaldehyde) KW - Polystyrene KW - Polyethylene KW - Flame retardancy KW - Fire retardant KW - Melamine resin KW - Polymer KW - Plasma PY - 2014 DO - https://doi.org/10.1080/01694243.2014.943339 SN - 0169-4243 SN - 1568-5616 VL - 28 IS - 21 SP - 2113 EP - 2132 PB - VNU Science Press CY - Utrecht AN - OPUS4-31485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Koter, Robert A1 - Hartelt, Manfred A1 - Spaltmann, Dirk A1 - Pentzien, Simone A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg T1 - Femtosecond laser-induced periodic surface structures on steel and titanium alloy for tribological applications N2 - Laser-induced periodic surface structures (LIPSS, ripples) were generated on stainless steel (100Cr6) and titanium alloy (Ti6Al4V) surfaces upon irradiation with multiple femtosecond laser pulses (pulse duration 30 fs, central wavelength 790 nm). The experimental conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning geometry for the processing of large surface areas (5 × 5 mm²) covered homogeneously by the nanostructures. The irradiated surface regions were subjected to white light interference microscopy and scanning electron microscopy revealing spatial periods around 600 nm. The tribological performance of the nanostructured surface was characterized by reciprocal sliding against a ball of hardened steel in paraffin oil and in commercial engine oil as lubricants, followed by subsequent inspection of the wear tracks. For specific conditions, on the titanium alloy a significant reduction of the friction coefficient by a factor of more than two was observed on the laser-irradiated (LIPSS-covered) surface when compared to the non-irradiated one, indicating the potential benefit of laser surface structuring for tribological applications. PY - 2014 DO - https://doi.org/10.1007/s00339-014-8229-2 SN - 0947-8396 VL - 117 IS - 1 SP - 103 EP - 110 PB - Springer CY - Berlin AN - OPUS4-31450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fettig, Ina A1 - Krüger, Simone A1 - Deubel, Jan A1 - Werrel, Martin A1 - Raspe, Tina A1 - Piechotta, Christian T1 - Evaluation of a headspace solid-phase microextraction method for the analysis of ignitable liquids in fire debris N2 - The chemical analysis of fire debris represents a crucial part in fire investigations to determine the cause of a fire. A headspace solid-phase microextraction (HS-SPME) procedure for the detection of ignitable liquids in fire debris using a fiber coated with a mixture of three different sorbent materials (Divinylbenzene/Carboxen/Polydimethylsiloxane, DVB/CAR/PDMS) is described. Gasoline and diesel fuel were spiked upon a preburnt matrix (wood charcoal), extracted and concentrated with HS-SPME and then analyzed with gas chromatography/mass spectrometry (GC/MS). The experimental conditions—extraction temperature, incubation and exposure time—were optimized. To assess the applicability of the method, fire debris samples were prepared in the smoke density chamber (SDC) and a controlled-atmosphere cone calorimeter. The developed methods were successfully applied to burnt particleboard and carpet samples. The results demonstrate that the procedure that has been developed here is suitable for detecting these ignitable liquids in highly burnt debris. KW - Forensic science KW - Arson analysis KW - Fire debris KW - Ignitable liquids KW - Solid-phase microextraction KW - Smoke density chamber KW - Cone calorimeter PY - 2013 DO - https://doi.org/10.1111/1556-4029.12342 SN - 0022-1198 SN - 1556-4029 VL - 59 IS - 3 SP - 743 EP - 749 PB - Wiley CY - Hoboken, NJ, USA AN - OPUS4-30038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bonse, Jörn A1 - Kirner, Sabrina A1 - Koter, Robert A1 - Pentzien, Simone A1 - Spaltmann, Dirk A1 - Krüger, Jörg T1 - Femtosecond laser-induced periodic surface structures on titanium nitride coatings for tribological applications N2 - Titanium nitride (TiN) was coated on different substrate materials, namely pure titanium (Ti), titanium alloy (Ti6Al4V) and steel (100Cr6), generating 2.5 μm thick TiN layers. Using femtosecond laser pulses (30 fs, 790 nm, 1 kHz pulse repetition rate), large surface areas (5 mm × 5 mm) of laser-induced periodic surface structures (LIPSS) with sub-wavelength periods ranging between 470 nm and 600 nm were generated and characterized by optical microscopy (OM), white light interference microscopy (WLIM) and scanning electron microscopy (SEM). In tribological tests, coefficients of friction (COF) of the nanostructured surfaces were determined under reciprocating sliding conditions (1 Hz, 1.0 N normal load) against a 10-mm diameter ball of hardened 100Cr6 steel during 1000 cycles using two different lubricants, namely paraffin oil and engine oil. It turned out that the substrate material, the laser fluence and the lubricant are crucial for the tribological performance. However, friction and wear could not be significantly reduced by LIPSS on TiN layers in comparison to unstructured TiN surfaces. Finally, the resulting wear tracks on the nanostructured surfaces were investigated with respect to their morphology (OM, SEM), depth (WLIM) and chemical composition by energy dispersive X-ray spectroscopy (EDX) and, on one hand, compared with each other, on the other hand, with non-structured TiN surfaces. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Titanium nitride films KW - Friction KW - Wear PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0169433216322486 DO - https://doi.org/10.1016/j.apsusc.2016.10.132 SN - 0169-4332 SN - 1873-5584 VL - 418 IS - Part B SP - 572 EP - 579 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-40507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Deubel, Jan A1 - Werrel, Martin A1 - Fettig, Ina A1 - Raspe, Tina T1 - Experimental studies on the effect of fire accelerants during living room fires and detection of ignitable liquids in fire debris N2 - Reconstructing the course of a fire and performing chemical analysis of ignitable liquids in fire debris is an important tool to conduct fire investigations in suspected arson cases. Here, a total of five fire tests has been performed to investigate the effect of fire accelerants on the fire development of a room fire and to prove the capability of analytical methods. Different experimental scenarios have been realized (no accelerant, accelerant applied at different positions, and different amounts of fire accelerant). Each test room was equipped with an identical set of living room furnishing. The location and amount of the fire accelerant applied löschen varied in four of five tests. One experiment was carried out without fire accelerant. Fire quantities such as mass loss (of the entire room), gas temperatures (at several locations in the room), and heat release were determined during the experiments, and chemical-analytical studies were carried out. A headspace solid phase micro extraction procedure, using gas chromatography–mass spectrometry, was used to analyze fire debris samples to potentially detect ignitable liquids. Beside the analysis of fire debris samples, swipe soot samples were analyzed and the detectability of the fire accelerant used was demonstrated. Results show that it is possible to provide evidence of ignitable liquids in soot samples collected from walls. This allows an additional sampling strategy at potential crime scenes, besides taking fire debris samples. KW - Fire behavior KW - Room fire test KW - Heat release KW - Temperatures KW - Fire debris KW - Ignitable liquids KW - Solid phase microextraction KW - Gas chromatography PY - 2015 DO - https://doi.org/10.1002/fam.2263 SN - 0308-0501 SN - 1099-1018 VL - 39 IS - 7 SP - 636 EP - 646 PB - Heyden CY - London AN - OPUS4-34550 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Despinasse, Marie-Claire A1 - Raspe, Tina A1 - Nörthemann, K. A1 - Moritz, W. T1 - Early fire detection: Are hydrogen sensors able to detect pyrolysis of house hold materials? N2 - We analysed the hydrogen generation during the smouldering of polymeric materials, which are typically used in the household, in the Smoke Density Chamber coupled to a new developed hydrogen sensor to detect early stages of fires. The results of hydrogen generation were compared with the emission of carbon monoxide and smoke during the fire scenarios. Additionally, the results were compared with parameters used in traditional commercial detection systems. In this scenario, the hydrogen sensor showed encouraging results for the detection of fires in earlier phase compared to traditional detectors. Furthermore, we tested the new developed hydrogen sensor in a real room with different fire scenarios. We have also investigated interferences, e.g. steam and cigarette smoke. The hydrogen sensor could detect hydrogen generation in the earliest stage of fire, even before CO and smoke were developed in detectable amounts. Therefore, the hydrogen sensor can be applied for early fire detection in case of pyrolysis. The sensors are quite good for detecting pyrolysis gases. But when it comes to a fast ignition other techniques are more suitable for it. The sensors are best for combination with other techniques, such as smoke detectors. T2 - IAFSS 12th Symposium 2017 CY - Lund, Sweden KW - Fire chemistry KW - Hydrogen sensor PY - 2017 DO - https://doi.org/10.1016/j.firesaf.2017.04.035 SN - 0379-7112 SN - 1873-7226 VL - 91 SP - 1059 EP - 1067 PB - Elsevier AN - OPUS4-41895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -