TY - JOUR A1 - Mitzkus, Anja A1 - Sahre, Mario A1 - Reinstädt, Philipp A1 - Griepentrog, Michael A1 - Beck, Uwe A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Basedau, Frank A1 - Hofmann, Detlef A1 - Gong, Xin A1 - Schukar, Vivien T1 - Altbekannter Watts-Elektrolyt, junge Hightech-Anwendung, Nickel- und Nickel-Eisen-Schichten als magnetostriktive Aktorschicht auf faseroptischen Sensoren JF - WoMAG N2 - Durch faseroptische Sensoren können Bauteile im Einsatz kontinuierlich überwacht und frühzeitig Informationen über Materialveränderungen gewonnen werden. Mittels einer magnetostriktiven Aktorschicht, welche den Sensor umhüllt, kann nun auch die korrekte Sensorfunktion jederzeit kontrolliert werden. Als Aktorschicht eignet sich galvanisch abgeschiedenes reines Nickel oder Nickel-Eisen in der Zusammensetzung 50:50. Um diese haftfest mit dem Sensor zu verbinden wurde ein ECD/PVD-Kombinationsschichtsystem entwickelt. Die mechanischen Eigenschaften der ECD-Schicht können sowohl mit einer auf die Fasergeometrie angepassten instrumentierten Eindringprüfung als auch einem 2-Punkt-Biegeversuch bestimmt werden. KW - Faseroptik-Sensoren KW - ECD-Aktorschicht KW - PVD-Haftfestigkeit KW - Nickel-/Nickel-Eisen- Magnetostriktion PY - 2016 SN - 2195-5891 SN - 2195-5905 VL - 12 SP - 1 EP - 4 AN - OPUS4-39129 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Asadi, S. A1 - Schiller, J.H. A1 - Lilienthal, A.J. A1 - Bartholmai, Matthias T1 - An artificial potential field based sampling strategy for a gas-sensitive micro-drone T2 - IEEE/RSJ International conference on intelligent robots and systems (IROS '11) / Workshop on robotics for environmental monitoring (WREM2011) N2 - This paper presents a sampling strategy for mobile gas sensors. Sampling points are selected using a modified artificial potential field (APF) approach, which balances multiple criteria to direct sensor measurements towards locations of high mean concentration, high concentration variance and areas for which the uncertainty about the gas distribution model is still large. By selecting in each step the most often suggested close-by measurement location, the proposed approach introduces a locality constraint that allows planning suitable paths for mobile gas sensors. Initial results in simulation and in real-world experiments with a gas-sensitive micro-drone demonstrate the suitability of the proposed sampling strategy for gas distribution mapping and its use for gas source localization. T2 - IEEE/RSJ International conference on intelligent robots and systems (IROS '11) / Workshop on robotics for environmental monitoring (WREM2011) CY - San Francisco, CA, USA DA - 25.09.2011 KW - Autonomous UAV KW - Chemical sensing KW - Gas distribution modelling KW - Gas source localization KW - Gas sensors KW - Mobile sensing system KW - Quadrocopter KW - Sensor planning KW - Artificial potential field PY - 2011 SP - 34 EP - 38 AN - OPUS4-24537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartholmai, Matthias A1 - Schartel, Bernhard T1 - Assessing the performance of intumescent coatings using bench-scaled cone calorimeter and finite difference simulations JF - Fire and materials N2 - A method was developed to assess the heat insulation performance of intumescent coatings. The method consists of temperature measurements using the bench-scaled experimental set-up of a cone calorimeter and finite difference simulation to calculate the effective thermal conductivity dependent on time/temperature. This simulation procedure was also adapted to the small scale test furnace, in which the standard time-temperature curve is applied to a larger sample and thus which provides results relevant for approval. Investigations on temperature and calculated effective thermal conduction were performed on intumescent coatings in both experimental set-ups using various coating thicknesses. The results correspond to each other as well as showing the limits of transferability between both fire tests. It is shown that bench-scaled cone calorimeter tests are a valuable tool for assessing and predicting the performance of intumescent coatings in larger tests relevant for approval. The correlation fails for processes at surface temperatures above 750°C, which are not reached in the cone calorimeter, but are attained in the small scale furnace set-up. KW - Intumescent coatings KW - Cone calorimetry KW - Numerical analysis KW - Small scale test furnace PY - 2007 SN - 0308-0501 SN - 1099-1018 VL - 31 IS - 3 SP - 187 EP - 205 PB - Heyden CY - London AN - OPUS4-14645 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moufid, M. A1 - Bouchikhi, B. A1 - Tiebe, Carlo A1 - Bartholmai, Matthias A1 - El Bari, N. T1 - Assessment of outdoor odor emissions from polluted sites using simultaneous thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS), electronic nose in conjunction with advanced multivariate statistical approaches JF - Atmospheric Environment N2 - Poor air quality, particularly in urban areas, causes various diseases and degrades living standards. Air Quality could be affected by emissions of odor, Volatile Organic Compounds (VOCs), and other gases. Therefore, assessment and monitoring of odorous air quality using sensitive, simple, rapid, accurate and portable tools is very important for public health. This study aimed to characterize odor emissions to detect malfunctions in facilities and to prevent air pollution and olfactory nuisance in the environment. A gas chromatographic method, in conjunction with sensorial analysis were performed for odorous air samples analysis collected from neighborhood of Meknes city (Morocco). Advanced multivariate statistical approaches, such as Principal Components Analysis (PCA), Discriminant Function Analysis (DFA), Support Vector Machines (SVMs), and Hierarchical Cluster Analysis (HCA), were used to describe samples similarities. The electronic nose (e-nose) data processing exhibits a satisfactory discrimination between the odorous air samples. Twenty-four VOCs with known molecular formulas were identified with Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS). A validated Partial Least Square (PLS) model foresees good calibration between e-nose measurement and TD-GCMS analysis. The finding indicates that TD-GC–MS approach in conjunction with e-nose unit could be suitable tool for environmental measurement-based odor emissions. KW - Electronic nose KW - TD-GC-MS KW - PLS regression KW - Multivariate analysis KW - Outdoor odor emissions PY - 2021 DO - https://doi.org/10.1016/j.atmosenv.2021.118449 SN - 1352-2310 VL - 256 SP - 118449 PB - Elsevier Ltd. AN - OPUS4-52626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Asadi, S. A1 - Lilienthal, A.J. A1 - Bartholmai, Matthias A1 - Schiller, J.H. T1 - Autonomous gas-sensitive microdrone - wind vector estimation and gas distribution mapping JF - IEEE Robotics and automation magazine N2 - This article presents the development and validation of an autonomous, gas sensitive microdrone that is capable of estimating the wind vector in real time using only the onboard control unit of the microdrone and performing gas distribution mapping (DM). Two different sampling approaches are suggested to address this problem. On the one hand, a predefined trajectory is used to explore the target area with the microdrone in a real-world gas DM experiment. As an alternative sampling approach, we introduce an adaptive strategy that suggests next sampling points based on an artificial potential field (APF). Initial results in real-world experiments demonstrate the capability of the proposed adaptive sampling strategy for gas DM and its use for gas source localization. KW - Anemometric sensor KW - Autonomous micro UAV KW - Chemical sensing KW - Gas distribution modelling KW - Gas source localization KW - Gas sensors KW - Mobile sensing system KW - Quadrocopter KW - Sensor planning KW - Artificial potential field PY - 2012 DO - https://doi.org/10.1109/MRA.2012.2184671 SN - 1070-9932 VL - 19 IS - 1 SP - 50 EP - 61 PB - IEEE CY - New York, NY, USA AN - OPUS4-25773 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Braun, Ulrike ED - Le Bras, M. T1 - Barrier effects for the fire retardancy of polymers T2 - Fire retardancy of polymers T2 - 9th European Meeting on Fire Retardancy and Protection of Materials CY - Lille, France DA - 2003-09-15 KW - Fire retardancy KW - Nanocomposites KW - Red Phosphorus KW - Mg(OH)2 KW - Cone Calorimeter KW - LOI PY - 2005 SN - 0-85404-582-1 VL - 9 SP - 264 EP - 275 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-7377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Köppe, Enrico T1 - Bauwerke unter Beobachtung. Funkbasiertes Sensornetzwerk zur Schadensfrüherkennung an Bauwerken T2 - Hannover-Messe T2 - Hannover-Messe CY - Hanover, Germany DA - 2010-04-19 PY - 2010 AN - OPUS4-22058 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manolov, Manol A1 - Subaric-Leitis, Andreas A1 - Bartholmai, Matthias T1 - Bestimmung der Maschinennachgiebigkeit beim Einsatz sphärischer Indenter in der Instrumentierten Eindringprüfung T2 - ITG-Fachbericht 281 Sensoren und Messsysteme 2018 N2 - Es wird ein vereinfachtes Verfahren für die Bestimmung und Implementierung der Maschinennachgiebigkeit bei der Verwendung eines sphärischen Indenters dargestellt. Die Maschinennachgiebigkeit wird bei deutlicher Kraftabhängigkeit als Funktion der Kraft in die Auswertung implementiert. Als sensitiver Kennwert dient der aus der instrumentierten Eindringprüfung an Härtevergleichsplatten ermittelte Eindringmodul. T2 - Sensoren und Messsysteme CY - Nürnberg, Germany DA - 26.06.2018 KW - Maschinennachgiebigkeit KW - Instrumentierte Eindringprüfung KW - Sphärische Indenter KW - Vereinfachtes Verfahren KW - Kraftabhängige Funktion KW - Härtevergleichsplatten KW - Eindringmodul PY - 2018 SN - 978-3-8007-4683-5 SN - 0932-6022 VL - 19. ITG/GMA-Fachtagung SP - 565 EP - 569 PB - VDE Verlag GmbH CY - Berlin AN - OPUS4-45394 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Melzer, Michael A1 - Fischer, Michael A1 - Thomas, Marcus A1 - Subaric-Leitis, Andreas A1 - Bartholmai, Matthias T1 - Calibration Service as a Gateway to Sustainable Research and Development T2 - SMSI 2020 Proceedings N2 - Over decades, the German Federal Institute for Materials Research and Testing (BAM) has established a sophisticated calibration laboratory for force, temperature and electrical quantities. Since more than 15 years it is accredited, currently by the national accreditation body (DAkkS), and offers its service also to external entities on a global scale. As a public provider, we are furthermore committed to research and development activities that demand measurements with highest quality and low level of uncertainties. Two R&D examples are highlighted within this contribution. T2 - SMSI 2020 CY - Meeting was canceled DA - 22.06.2020 KW - Calibration of force KW - Calibration of temperature KW - Calibration of electrical quantities KW - Measurement uncertainty KW - New sensor principles PY - 2020 SN - 978-3-9819376-2-6 DO - https://doi.org/10.5162/SMSI2020/E3.3 SP - 374 EP - 375 AN - OPUS4-51222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph T1 - Chances and limitations of RFID sensor systems – practical experiences from research projects with different application scenarios N2 - The combination of Radio-frequency identification (RFID) and low energy sensors offers promising chances to implement cost effective, easy to apply, and easy to handle sensor systems for a variety of applications. The RFID technology is already well established in logistics. Enhanced processing and interface capabilities enable the integration of various sensors for control, diagnostics, and monitoring tasks. In the scope of research projects carried out at the Federal Institute for Materials Research and Testing (BAM), RFID sensor systems were developed and validated with regard to two different application scenarios: the Identification and diagnosis of concrete components for road bridges and the monitoring of dangerous goods transportation. This contribution presents selected research results and reflects the practical experiences on future chances and limitations of RFID sensor systems. T2 - IDTechEx Show! Europe 2016 CY - Berlin, Germany DA - 27.04.2016 KW - RFID Sensors systems KW - Diagnosis of concrete components KW - Monitoring of dangerous goods PY - 2016 AN - OPUS4-36034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lazik, D. A1 - Ebert, S. A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias T1 - Characteristic length measurement of a subsurface gas anomaly - A monitoring approach for heterogeneous flow path distributions JF - International Journal of Greenhouse Gas Control N2 - Geogenic gases from natural sources, carbon dioxide (CO2) from a geological repository (carbon capture and storage - CCS) or a leaking gas pipeline can present serious risks in industrial and urban areas. To extend the lead time for risk treatment in such critical regions, reliable detection of gases within the shallow subsurface is required to observe critical gas accumulations before degassing into the atmosphere. A near real-time monitoring approach is introduced to determine the volumetric expansion of a leakinggas in the subsurface. Considering the pressure relaxation with the ambient air pressure, the approach enables the forecasting of the final size of a pressurized gas body in terms of characteristic lengths. According to theoretical basics, such a characteristic length, which enables us to perform a gas (safety) measurement based on a purely geometrical measure, behaves independently of subsurface properties,i.e., it enables a reliable quantification of the escaping gas irrespective of its heterogeneous or changingflow path distribution. A field test for a 10 l/min pinhole leakage injected into a 10 m long, 0.4 m wide, 0.95 m deep soil-filled trench that was equipped with linear sensors shows the lateral-vertical volumetric gas expansion along these sensors, and demonstrates the applicability of the characteristic length approach. KW - Monitoring KW - Carbon capture and storage KW - Leakage KW - Quantification KW - Subsurface KW - CO2 PY - 2016 DO - https://doi.org/10.1016/j.ijggc.2016.02.008 SN - 1750-5836 VL - 2016 IS - 47 SP - 330 EP - 341 PB - Elsevier B.V. AN - OPUS4-35425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lazik, D. A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias A1 - Ebert, Sebastian T1 - Characteristic length measurement of a subsurface gas anomaly - an integrating monitoring approach over heterogeneous distributed gas flow paths N2 - Geogenic gases such as CH4 or CO2 from natural sources, gases (CCS-CO2, H2, Natural gas, City gas …) from a geological repository, or a leaking gas pipeline can present serious risks in industrial and urban areas where the density of infrastructural elements increases as well as above and below ground. To extend the lead time for risk treatment in such critical regions, reliable detection of gases within the shallow subsurface is required to observe critical gas accumulations before degassing into the atmosphere. A near real-time monitoring approach is introduced to determine the volumetric expansion of such a gas escaping from a leak in the subsurface. Considering the pressure relaxation with the ambient air pressure, the approach enables the forecasting of the final size of a pressurized gas body in terms of characteristic lengths. According to theoretical basics, such a characteristic length, which allows to perform a gas (safety) measurement based on a purely geometrical measure, behaves independently of subsurface properties, i.e., it enables a reliable quantification of the escaping gas, irrespective of its heterogeneous flow path distribution. A field test for a 10 l/min pinhole leakage of CO2 injected in an unsaturated Chernozemic soil (agricultural test field Bad Lauchstädt)that was equipped with linear gas sensors demonstrates the lateral-vertical volumetric gas expansion along the environment of these gas sensors, and confirms the applicability of the new characteristic length approach. T2 - UFZ EnergyDays 2017 CY - Leipzig, Germany DA - 15.03.2017 KW - CO2 KW - Carbon capture and storage KW - Leakage KW - Monitoring PY - 2017 AN - OPUS4-39400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Johann, Sergej A1 - Bartholmai, Matthias A1 - Werner, Klaus-Dieter A1 - Daum, Werner T1 - Characterization of the temperature behavior of a piezoresistive accelerometer N2 - Piezoresistive accelerometers use a strainsensing element, generally made of semiconductor material, e.g., silicon to convert the mechanical motion into an electrical signal. This element is usually designed in form of a cantilever beam loaded with a mass. Acceleration causes bending of the beam, which produces a change of electrical resistance proportional to the applied acceleration. Main advantages of piezoresistive accelerometers in comparison to other types, e.g., piezoelectric and capacitive, is their robust and highly dynamic behavior, which qualifies them for application in high impact shock applications. Mechanical damping is typically implemented with silicon oil in a way that the output signal is undistorted over a wide frequency range. These characteristics principally qualify them for the application in drop tests carried out at BAM, for which they are calibrated over the frequency range from 1 to 4 kHz. However, using silicon oil for damping, has the drawback of temperature dependent change of its viscosity, leading to temperature dependent deviation of the accelerometer’s sensitivity. This study presents experimental results of the temperature behavior of a piezoresistive accelerometer with a dynamic range up to ±5000 g. This type of accelerometer is applied for drop tests which are partially performed at temperatures of -40 or +100 °C. T2 - 34th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - Piezoresistive accelerometers KW - Temperature behavior of a piezoresistive accelerometer KW - Hopkinson bar KW - Drop tests PY - 2017 AN - OPUS4-42095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Werner, Klaus-Dieter A1 - Johann, Sergej A1 - Daum, Werner ED - Cosmi, F. T1 - Characterization of the temperature behavior of a piezoresistive accelerometer T2 - 34rd Danubia - Adria Symposium on Advances in Experimental Mechanics - Book of proceedings N2 - Piezoresistive accelerometers use a strain-sensing element, generally made of semiconductor material, e.g., silicon to convert the mechanical motion into an electrical signal. This element is usually designed in form of a cantilever beam loaded with a mass. Acceleration causes bending of the beam, which produces a change of electrical resistance proportional to the applied acceleration. Main advantages of piezoresistive accelerometers in comparison to other types, e.g., piezoelectric and capacitive, is their robust and highly dynamic behavior, which qualifies them for application in high impact shock applications. Mechanical damping is typically implemented with silicon oil in a way that the output signal is undistorted over a wide frequency range. These characteristics principally qualify them for the application in drop tests carried out at BAM, for which they are calibrated over the frequency range from 1 to 4 kHz. However, using silicon oil for damping, has the drawback of temperature dependent change of its viscosity, leading to temperature dependent deviation of the accelerometer’s sensitivity. This study presents experimental results of the temperature behavior of a piezoresistive accelerometer with a dynamic range up to ±5000 g. This type of accelerometer is applied for drop tests which are partially performed at temperatures of -40 or +100 °C. T2 - 34th Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Trieste, Italy DA - 19.09.2017 KW - Accelerometer KW - Temperature behavior KW - Drop test PY - 2017 UR - https://www.openstarts.units.it/handle/10077/14921 SN - 978-88-8303-863-1 SP - 93 EP - 95 CY - Trieste AN - OPUS4-42109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moufid, M. A1 - Tiebe, Carlo A1 - El Bari, N. A1 - Bartholmai, Matthias A1 - Bouchikhi, B. T1 - Characterization of Unpleasant Odors in Poultry Houses Using Metal Oxide Semiconductor-Based Gas Sensor Arrays and Pattern Recognition Methods T2 - The 1st International Electronic Conference on Chemical Sensors and Analytical Chemistry) N2 - In this study, the ability of an electronic nose developed to analyze and monitor odor emissions from three poultry farms located in Meknes (Morocco) and Berlin (Germany) was evaluated. Indeed, the potentiality of the electronic nose (e-nose) to differentiate the concentration fractions of hydrogen sulfide, ammonia, and ethanol was investigated. Furthermore, the impact change of relative humidity values (from 15% to 67%) on the responses of the gas sensors was reported and revealed that the effect remained less than 0.6%. Furthermore, the relevant results confirmed that the developed e-nose system was able to perfectly classify and monitor the odorous air of poultry farms. T2 - 1st International Electronic Conference on Chemical Sensors and Analytical Chemistry CY - Online meeting DA - 01.07.2021 KW - Pattern recognition methods KW - Gas sensors KW - Electronic nose KW - poultry odorous air monitoring PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544005 UR - https://csac2021.sciforum.net/ DO - https://doi.org/10.3390/CSAC2021-10481 VL - 5 IS - 52 SP - 1 EP - 7 PB - MDPI AN - OPUS4-54400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moufid, M. A1 - Tiebe, Carlo A1 - El Bari, N. A1 - Bartholmai, Matthias A1 - Bouchikhi, B. T1 - Combining of TD-GC-MS and home developed electronic nose for road traffic air monitoring T2 - 2021 IEEE International Conference on Design & Test of Integrated Micro & Nano-Systems (DTS) N2 - In this work, we demonstrate the ability of an electronic nose system based on an array of six-semiconductor gas sensors for outdoor air quality monitoring over a day at a traffic road in downtown of Meknes city (Morocco). The response of the sensor array reaches its maximum in the evening of the investigated day which may due to high vehicular traffic or/and human habits resulting in elevated concentrations of pollutants. Dataset treatment by Principal Component Analysis and Discriminant Function Analysis shows a good discrimination between samples collected at different times of the day. Moreover, Support Vector Machines were used and reached a classification success rate of 97.5 %. Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS) technique was used to validate the developed e-nose system by identifying the composition of the analyzed air samples. The discrimination obtained by e-nose system was in good agreement with the TD-GC-MS results. This study demonstrates the usefulness of TD-GC-MS and e-nose, providing high accuracy in discriminating outdoor air samples collected at different times. This demonstrates the potential of using the e-nose as a rapid, easy to use and inexpensive environmental monitoring system. T2 - 2021 IEEE International Conference on Design & Test of Integrated Micro & Nano-Systems (DTS) CY - Sfax, Tunisia DA - 07.06.2021 KW - GC-MS KW - Electronic nose KW - Gas sensors KW - Urban air monitoring PY - 2021 DO - https://doi.org/10.1109/DTS52014.2021.9498110 SP - 1 EP - 6 AN - OPUS4-54401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hartwig, A. A1 - Pütz, D. A1 - Schartel, Bernhard A1 - Bartholmai, Matthias A1 - Wendschuh-Josties, M. T1 - Combustion behaviour of epoxide based nanocomposites with ammonium and phosponium bentonites JF - Macromolecular chemistry and physics N2 - The influence of different organobentonites on the decomposition and the combustion behaviour of an epoxy resin were examined. The epoxy resin is a cationically polymerised cycloaliphatic epoxy resin flexibilised with poly(tetrahydrofuran) (PTHF), with hydroxyl endgroups. The bentonite was modified with either an ammonium or a phosphonium salt. The thermal decomposition of the PTHF induced by the initiator, used for the cationic polymerisation, did neither take place for the nanocomposite based on the ammonium bentonite nor for that based on the phosphonium bentonite. This improved decomposition characteristic lead to a larger time to ignition for both kinds of nanocomposites compared to the not modified polymer, which is not the case for other polymer/clay nanocomposites described in the literature. The fire behaviour was investigated using limiting oxygen index (LOI), a horizontal burner test and a cone calorimeter. The forced flaming conditions in the cone calorimeter were varied using different external heat fluxes between 30 and 70 kW · m-2. The fire behaviour of the nanocomposites was improved in comparison to the polymer, and phosphonium bentonite was superior to ammonium bentonite. The main mechanism is a barrier formation resulting in a reduction of the fire growth rate, which was more pronounced in the case of high external heat fluxes. KW - Cationic polymerisation KW - Clay KW - Combustion KW - Degradation KW - Epoxide KW - Nanocomposite PY - 2003 DO - https://doi.org/10.1002/macp.200300047 SN - 1022-1352 SN - 1521-3935 VL - 204 IS - 18 SP - 2247 EP - 2257 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-2801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Werner, Klaus-Dieter T1 - Comparison of the Temperature Behavior of Oil and Gas Damped Piezoresistive Accelerometers N2 - This study presents the characterization of a piezoresistive accelerometer damped with silicon oil for the application in drop tests carried out at BAM. Experiments were performed with the Hopkinson Bar method in close correlation to the real-world application conditions. The results point out certain limitations regarding the temperature influence and the frequency response. Additional experiments were performed with a gas damped type of piezoresistive accelerometer, which has superior specifications, particularly for low temperatures. The results allow for a comparison. T2 - IEEE SENSORS 2018 CY - Neu Delhi, Indien DA - 28.10.2018 KW - Accelerometer KW - Temperature behavior KW - Frequency response KW - Hopkinson Bar KW - Drop test PY - 2018 AN - OPUS4-46484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Schartel, Bernhard T1 - Comprehensive Fire Behaviour Assessment of Nanocomposites T2 - 9th European Meeting on Fire Retardancy and Protection of Materials, FRPM '03 T2 - 9th European Meeting on Fire Retardancy and Protection of Materials, FRPM '03 CY - Lille, France DA - 2003-09-17 PY - 2003 AN - OPUS4-4615 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Neumann, Patrick P. A1 - Ebert, Sebastian A1 - Lazik, D. T1 - Comprehensive Monitoring of Structures for Gas Transport and Storage using Linear Multi-Sensors T2 - World Congress of Smart Materials 2015 (WCSM-2015) T2 - World Congress of Smart Materials 2015 (WCSM-2015) CY - Busan, Korea DA - 2015-03-23 PY - 2015 AN - OPUS4-32930 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -