TY - CHAP A1 - Galle, Bo A1 - Arellano, Santiago A1 - Conde, Vladimir A1 - Pfeffer, Melissa A1 - Barsotti, Sara A1 - Stefansdottir, Gerður A1 - Bergsson, Baldur A1 - Bergsson, Bergur A1 - Ingvarsson, Thorgils A1 - Weber, Konradin T1 - Ground based measurements of the gas emission from the Holuhraun volcanic fissure eruption on Iceland 2014/2015 T2 - Geophysical Research Abstracts: EGU General Assembly 2015 N2 - The since 31 August 2014 ongoing volcanic eruption at Holuhraun on Iceland is by far the strongest source of sulfur dioxide in Europe over the last 230 years with sustained emission rates exceeding 100 000 ton/day. This gas emission severely affects local population and has become a concern also for air traffic. The eruption has in December continued at constant pace for 3.5 months. Three scenarios are envisaged for the future; (1) the eruption stops, (2) the fissure extends under the Vattnajökul glacier and (3) Bardarbunga volcano erupts. The two later scenarios will cause increased gas emission, severe ash emissions and extended flooding. Under the scope of the EU-project FUTUREVOLC, a project with 3.5 years duration, aiming at making Iceland a supersite for volcanological research as a European contribution to GEO, we are developing a version of the Scanning DOAS instrument that is adapted to high latitudes with low UV radiation and severe meteorological conditions. Since the first day of the eruption several of these novel instruments has been monitoring the SO2 emission from the eruption. Data from our instruments are still after 3.5 months the only sustained ground-based monitoring of this gas emission. A lot of work is however needed to sustain this operation at a very remote site and under severe field conditions. At the same time the very high concentrations in the gas plume, in combination with bad meteorological conditions require the development of novel methods to derive reliable flux estimates. In this presentation we will discuss the instrumental issues and present the latest version of the emission estimates made from our measurements. KW - Luftreinhaltung KW - Vulkanismus KW - Messtechnik KW - Schwefeldioxid Y1 - 2015 UR - https://web.archive.org/web/20240616051633/https://meetingorganizer.copernicus.org/EGU2015/EGU2015-1722-1.pdf N1 - Vortragsabstract VL - 17 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Galban, Craig A1 - Maderwald, Stefan A1 - Herrmann, Burkhard A1 - Brauck, K. A1 - Grote, Wolfgang A1 - de Greiff, A. A1 - Uffmann, K. A1 - Ladd, M. T1 - Measuring Skeletal Muscle Elasticity in Patients with Hypogonadism by MR Elastography JF - Proc. Intl. Soc. Mag. Reson. Med. N2 - Men afflicted with hypogonadism have reduced fat-free mass and in some cases a loss in muscle strength. We hypothesize that muscle elasticity of the lower extremities differs between patients with hypogonadism and healthy controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0%, 5%, 10%, 15%, and 20% of the subject’s maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in applied force. Y1 - 2005 UR - https://cds.ismrm.org/protected/05MProceedings/PDFfiles/02016.pdf VL - 13 SP - 2016 ER - TY - JOUR A1 - Galban, Craig A1 - Maderwald, Stefan A1 - Eggebrecht, Holger A1 - Grote, Wolfgang A1 - de Greiff, A. A1 - Uffmann, K. A1 - Ladd, M. E. T1 - Monitoring the Effects of Chronic Obstructive Pulmonary Disease on Muscle Elasticity by MR Elastography JF - Proc. Intl. Soc. Mag. Reson. Med. N2 - Men afflicted with chronic obstructive pulmonary disease (COPD) show signs of muscle dysfunction, such as increased muscle fatigue and acidosis during exercise. We hypothesize that muscle elasticity of the lower extremities differs between patients with COPD and age-related controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0%, 5%, 10%, 15%, and 20% of the subject’s maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in the maximum applied force. Y1 - 2005 UR - https://cds.ismrm.org/protected/05MProceedings/PDFfiles/02015.pdf VL - 13 SP - 2015 ER - TY - JOUR A1 - Gaida, Philipp A1 - Weinberg, Kerstin A1 - Jahr, Andreas T1 - Viscoelastic modelling and experimental results of a dielectric electro-active polymer diaphragm actuator JF - Proceedings in Applied Mathematics and Mechanics (PAMM) Y1 - 2014 U6 - https://doi.org/10.1002/pamm.201410225 SN - 1617-7061 VL - 14 IS - 1 SP - 475 EP - 476 PB - Wiley ET - 85th Annual Meeting of the GAMM. March 10th – 14th, 2014, Erlangen ER - TY - CHAP A1 - Gaida, Philipp A1 - Jahr, Andreas A1 - Weinberg, Kerstin ED - Dłużewsk, Paweł ED - Jurczak, Grzegorz ED - Young, Toby D. T1 - FEA and experimental validation of an electroactive polymer actuator [Abstract] T2 - Third International Conference on Material Modelling incorporating the Thirteenth European Mechanics of Materials Conference, September 8–11, 2013,Warsaw, Poland Y1 - 2013 SN - 978-83-89687-83-8 IS - 185 PB - Instytut Podstawowych Problemów Techniki Polskiej Akademii Nauk CY - Warszawa ER - TY - CHAP A1 - Gaida, Philipp A1 - Jahr, Andreas A1 - Weinberg, Kerstin T1 - Preliminary survey of a diaphragm EAP stack for the use as an actuator in a water valve T2 - 14th International Workshop on Research and Education in Mechatronics 6th-7th June 2013 Y1 - 2013 ER - TY - CHAP A1 - Gaida, Daniel A1 - Wolf, Christian A1 - Stuhlsatz, André A1 - Lippel, Jens A1 - Bäck, T. A1 - Bongards, Michael A1 - McLoone, S. T1 - State Estimation for Anaerobic Digesters using the ADM1 T2 - Proceedings of International IWA-Symposium on Anaerobic Digestion of Solid Waste and Energy Crops, Vienna, Austria, 2011 Y1 - 2011 ER - TY - JOUR A1 - Gaida, Daniel A1 - Wolf, Christian A1 - Meyer, C. A1 - Stuhlsatz, André A1 - Lippel, Jens A1 - Bäck, T. A1 - Bongards, Michael A1 - McLoone, S. T1 - State estimation for anaerobic digesters using the ADM1 JF - Water science and technology N2 - The optimization of full-scale biogas plant operation is of great importance to make biomass a competitive source of renewable energy. The implementation of innovative control and optimization algorithms, such as Nonlinear Model Predictive Control, requires an online estimation of operating states of biogas plants. This state estimation allows for optimal control and operating decisions according to the actual state of a plant. In this paper such a state estimator is developed using a calibrated simulation model of a full-scale biogas plant, which is based on the Anaerobic Digestion Model No.1. The use of advanced pattern recognition methods shows that model states can be predicted from basic online measurements such as biogas production, CH4 and CO2 content in the biogas, pH value and substrate feed volume of known substrates. The machine learning methods used are trained and evaluated using synthetic data created with the biogas plant model simulating over a wide range of possible plant operating regions. Results show that the operating state vector of the modelled anaerobic digestion process can be predicted with an overall accuracy of about 90%. This facilitates the application of state-based optimization and control algorithms on full-scale biogas plants and therefore fosters the production of eco-friendly energy from biomass. Y1 - 2012 U6 - https://doi.org/10.2166/wst.2012.286 VL - 66 IS - 5 SP - 1088 EP - 1095 PB - IWA Publishing ER - TY - CHAP A1 - Gaida, Daniel A1 - Stuhlsatz, André A1 - Meier, Hans-Günter ED - Wendemuth, Andreas ED - Meier, Hans-Günter T1 - Fusion of Visual and Inertial Measurements for Pose Estimation T2 - Proceedings of the Workshop on Emotion-, Speech- and Face Recognition with Advanced Classifiers: Düsseldorf, Germany, May 16 - 17, 2008 ; 3rd joined research workshop between Otto-von-Guericke University Magdeburg and the University of Applied Sciences FH Düsseldorf Y1 - 2008 SN - 9783940961242 SP - 39 EP - 48 PB - Otto-von-Guericke University Magdeburg CY - Magdeburg ER - TY - CHAP A1 - Fussenecker, Claudia A1 - Niemann, Jörg A1 - Paul, Alexander A1 - Schlösser, Martin A1 - Schöning, Marius ED - Yilmaz, Murat ED - Niemann, Jörg ED - Clarke, Paul ED - Messnarz, Richard T1 - Educating Future Engineers – Meeting Challenges at Secondary School and University T2 - Systems, Software and Services Process Improvement Y1 - 2020 SN - 978-3-030-56440-7 U6 - https://doi.org/10.1007/978-3-030-56441-4_56 SP - 742 EP - 753 PB - Springer Nature Switzerland CY - Cham ER - TY - JOUR A1 - Fuchs, H. A1 - Hofzumahaus, A. A1 - Rohrer, F. A1 - Bohn, Birger A1 - Brauers, Theo A1 - Dorn, Hans-Peter A1 - Häseler, R. A1 - Holland, F. A1 - Kaminski, M. A1 - Li, X. A1 - Lu, K. A1 - Nehr, Sascha A1 - Tillmann, R. A1 - Wegener, R. A1 - Wahner, A. T1 - Experimental evidence for efficient hydroxyl radical regeneration in isoprene oxidation JF - Nature Geoscience KW - Luftreinhaltung Y1 - 2013 U6 - https://doi.org/10.1038/NGEO1964 SN - 1752-0894 VL - 6 IS - 12 SP - 1023 EP - 1026 PB - Springer Nature ER - TY - JOUR A1 - Fuchs, H. A1 - Dorn, Hans-Peter A1 - Bachner, M. A1 - Bohn, Birger A1 - Brauers, Theo A1 - Gomm, S. A1 - Hofzumahaus, A. A1 - Holland, F. A1 - Nehr, Sascha A1 - Rohrer, F. A1 - Tillmann, R. A1 - Wahner, A. T1 - Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration JF - Atmospheric Measurement Techniques N2 - Abstract. During recent field campaigns, hydroxyl radical (OH) concentrations that were measured by laser-induced fluorescence (LIF) were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK), methacrolein (MACR) and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD), China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS). Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s−1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points) yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03) × 106 cm−3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30–40% (median) larger than those by DOAS after MVK (20 ppbv) and toluene (90 ppbv) had been added. However, this discrepancy has a large uncertainty and requires further laboratory investigation. Observed differences between LIF and DOAS measurements are far too small to explain the unexpected high OH concentrations during the PRIDE-PRD2006 campaign. KW - Luftreinhaltung Y1 - 2012 U6 - https://doi.org/10.5194/amt-5-1611-2012 SN - 1867-8548 VL - 5 IS - 7 SP - 1611 EP - 1626 PB - Copernicus ER - TY - JOUR A1 - Fuchs, H. A1 - Bohn, Birger A1 - Hofzumahaus, A. A1 - Holland, F. A1 - Lu, K. D. A1 - Nehr, Sascha A1 - Rohrer, F. A1 - Wahner, A. T1 - Detection of HO2 by laser-induced fluorescence: calibration and interferences from RO2 radicals JF - Atmospheric Measurement Techniques N2 - Abstract. HO2 concentration measurements are widely accomplished by chemical conversion of HO2 to OH including reaction with NO and subsequent detection of OH by laser-induced fluorescence. RO2 radicals can be converted to OH via a similar radical reaction sequence including reaction with NO, so that they are potential interferences for HO2 measurements. Here, the conversion efficiency of various RO2 species to HO2 is investigated. Experiments were conducted with a radical source that produces OH and HO2 by water photolysis at 185 nm, which is frequently used for calibration of LIF instruments. The ratio of HO2 and the sum of OH and HO2 concentrations provided by the radical source was investigated and was found to be 0.50 ± 0.02. RO2 radicals are produced by the reaction of various organic compounds with OH in the radical source. Interferences via chemical conversion from RO2 radicals produced by the reaction of OH with methane and ethane (H-atom abstraction) are negligible consistent with measurements in the past. However, RO2 radicals from OH plus alkene- and aromatic-precursors including isoprene (mainly OH-addition) are detected with a relative sensitivity larger than 80 % with respect to that for HO2 for the configuration of the instrument with which it was operated during field campaigns. Also RO2 from OH plus methyl vinyl ketone and methacrolein exhibit a relative detection sensitivity of 60 %. Thus, previous measurements of HO2 radical concentrations with this instrument were biased in the presence of high RO2 radical concentrations from isoprene, alkenes or aromatics, but were not affected by interferences in remote clean environment with no significant emissions of biogenic VOCs, when the OH reactivity was dominated by small alkanes. By reducing the NO concentration and/or the transport time between NO addition and OH detection, interference from these RO2 species are suppressed to values below 20 % relative to the HO2 detection sensitivity. The HO2 conversion efficiency is also smaller by a factor of four, but this is still sufficient for atmospheric HO2 concentration measurements for a wide range of conditions. KW - Luftreinhaltung Y1 - 2011 U6 - https://doi.org/10.5194/amt-4-1209-2011 SN - 1867-8548 VL - 4 IS - 6 SP - 1209 EP - 1225 PB - Copernicus ER - TY - JOUR A1 - Fuchs, H. A1 - Acir, Ismail-Hakki A1 - Bohn, Birger A1 - Brauers, Theo A1 - Dorn, Hans-Peter A1 - Häseler, R. A1 - Hofzumahaus, A. A1 - Holland, F. A1 - Kaminski, M. A1 - Li, X. A1 - Lu, K. A1 - Lutz, A. A1 - Nehr, Sascha A1 - Rohrer, F. A1 - Tillmann, R. A1 - Wegener, R. A1 - Wahner, A. T1 - OH regeneration from methacrolein oxidation investigated in the atmosphere simulation chamber SAPHIR JF - Atmospheric Chemistry and Physics N2 - Abstract. Hydroxyl radicals (OH) are the most important reagent for the oxidation of trace gases in the atmosphere. OH concentrations measured during recent field campaigns in isoprene-rich environments were unexpectedly large. A number of studies showed that unimolecular reactions of organic peroxy radicals (RO2) formed in the initial reaction step of isoprene with OH play an important role for the OH budget in the atmosphere at low mixing ratios of nitrogen monoxide (NO) of less than 100 pptv. It has also been suggested that similar reactions potentially play an important role for RO2 from other compounds. Here, we investigate the oxidation of methacrolein (MACR), one major oxidation product of isoprene, by OH in experiments in the simulation chamber SAPHIR under controlled atmospheric conditions. The experiments show that measured OH concentrations are approximately 50% larger than calculated by the Master Chemical Mechanism (MCM) for conditions of the experiments (NO mixing ratio of 90 pptv). The analysis of the OH budget reveals an OH source that is not accounted for in MCM, which is correlated with the production rate of RO2 radicals from MACR. In order to balance the measured OH destruction rate, 0.77 OH radicals (1σ error: ± 0.31) need to be additionally reformed from each reaction of OH with MACR. The strong correlation of the missing OH source with the production of RO2 radicals is consistent with the concept of OH formation from unimolecular isomerization and decomposition reactions of RO2. The comparison of observations with model calculations gives a lower limit of 0.03 s−1 for the reaction rate constant if the OH source is attributed to an isomerization reaction of MACR-1-OH-2-OO and MACR-2-OH-2-OO formed in the MACR + OH reaction as suggested in the literature (Crounse et al., 2012). This fast isomerization reaction would be a competitor to the reaction of this RO2 species with a minimum of 150 pptv NO. The isomerization reaction would be the dominant reaction pathway for this specific RO2 radical in forested regions, where NO mixing ratios are typically much smaller. KW - Luftreinhaltung Y1 - 2014 U6 - https://doi.org/10.5194/acp-14-7895-2014 SN - 1680-7324 VL - 14 IS - 15 SP - 7895 EP - 7908 PB - Copernicus ER - TY - CHAP A1 - Friedrich, Linus A1 - Ruess, Martin A1 - Schröder, Kai-Uwe T1 - Efficient and robust shell design of space launcher vehicle structures T2 - 57th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, San Diego, 4-8 January 2016 Y1 - 2016 UR - https://arc.aiaa.org/doi/book/10.2514/MSDM16 SN - 978-1-62410-392-6 U6 - https://doi.org/10.2514/6.2016-1973 SP - 1 EP - 18 PB - American Institute of Aeronautics and Astronautics CY - Reston ER - TY - CHAP A1 - Friedrich, Linus A1 - Lyssakow, Pawel A1 - Pearce, Garth A1 - Ruess, Martin A1 - Bisagni, Chiara A1 - Schröder, Kai-Uwe ED - Papadrakakis, Manolis ED - Papadopoulos, V. ED - Stefanou, G. ED - Plevris, V. T1 - ON THE STRUCTURAL DESIGN OF IMPERFECTION SENSITIVE LAMINATED COMPOSITE SHELL STRUCTURES SUBJECTED TO AXIAL COMPRESSION T2 - Proceedings of the VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016), 05.06.2016 - 10.06.2016, Crete Island KW - composite shells KW - imperfection sensitivity KW - Shell buckling Y1 - 2016 UR - http://www.eccomasproceedia.org/conferences/eccomas-congresses/eccomas-congress-2016 SN - 978-618-82844-0-1 U6 - https://doi.org/10.7712/100016.1951.5838 SP - 2182 EP - 2189 PB - Institute of Structural Analysis and Antiseismic Research School of Civil Engineering National Technical University of Athens (NTUA) Greece CY - Athens ER - TY - JOUR A1 - Friedrich, Linus A1 - Loosen, Simon A1 - Liang, Ke A1 - Ruess, Martin A1 - Bisagni, Chiara A1 - Schröder, Kai-Uwe T1 - Stacking sequence influence on imperfection sensitivity of cylindrical composite shells under axial compression JF - Composite Structures Y1 - 2015 U6 - https://doi.org/10.1016/j.compstruct.2015.08.132 SN - 0263-8223 VL - 134 SP - 750 EP - 761 PB - Elsevier ER - TY - CHAP A1 - Franz, Thomas A1 - Staab, Steffen A1 - Arndt, Richard ED - Sleeman, Derek ED - Barker, Ken T1 - The X-COSIM integration framework for a seamless semantic desktop T2 - Proceedings of the 4th international conference on Knowledge capture Y1 - 2007 SN - 978-1-59593-643-1 U6 - https://doi.org/10.1145/1298406.1298433 N1 - Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee PB - ACM CY - New York, NY ER - TY - CHAP A1 - Franz, Thomas A1 - Staab, Steffen ED - Decker, Stefan ED - Park, Jack ED - Quan, Dennis ED - Sauermann, Leo T1 - SAM: Semantics Aware Instant Messaging for the Networked Semantic Desktop. revised and extended version T2 - Proceedings of the 1st Workshop On The Semantic Desktop. 4th International Semantic Web Conference Y1 - 2005 UR - http://www.thomas-franz.de/publications/franzstaab-sam.pdf N1 - This work is conducted with respect to the upcoming project Knowledge Sharing and Reuse across Media (X-Media), funded by the Information Society Technologies (IST) 6th Framework Programme. SP - 1 EP - 15 CY - Galway ER - TY - CHAP A1 - Franz, Thomas A1 - Sizov, Sergej ED - Rech, Jörg ED - Decker, Björn ED - Ras, Eric T1 - Communication Systems for Semantic Work Environments T2 - Emerging Technologies for Semantic Work Environments Y1 - 2008 UR - http://www.thomas-franz.de/publications/comm-for-swe.pdf U6 - https://doi.org/10.4018/978-1-59904-877-2.ch002 SP - 16 EP - 32 PB - IGI Global CY - Hershey ER -