TY - JOUR A1 - Zander, Nils A1 - Bog, Tino A1 - Elhaddad, Mohamed A1 - Espinoza, R. A1 - Hu, H. A1 - Joly, A. A1 - Wu, C. A1 - Zerbe, P. A1 - Düster, Alexander A1 - Kollmannsberger, Stefan A1 - Parvizian, J. A1 - Ruess, Martin A1 - Schillinger, Dominik A1 - Rank, Ernst T1 - FCMLab: A finite cell research toolbox for MATLAB JF - Advances in Engineering Software Y1 - 2014 U6 - https://doi.org/10.1016/j.advengsoft.2014.04.004 SN - 0965-9978 VL - 74 SP - 49 EP - 63 PB - Elsevier ER - TY - JOUR A1 - Senthur, N.S. A1 - Anand, C A1 - Ramesh Kumar, M A1 - Elumalai, P.V. A1 - Shajahan, Mohamed Iqbal A1 - Benim, Ali Cemal A1 - Nasr, Emad Abouel A1 - Hussein, H.M.A. A1 - Parthasarathy, M. T1 - Influence of cobalt chromium nanoparticles in homogeneous charge compression ignition engine operated with citronella oil JF - Energy Science & Engineering KW - General Energy KW - Safety, Risk, Reliability and Quality KW - DOAJ Y1 - 2022 U6 - https://doi.org/10.1002/ese3.1088 SN - 2050-0505 VL - 10 IS - 4 SP - 1251 EP - 1263 PB - Wiley ER - TY - CHAP A1 - Himmelein, H. A1 - Steffens, Jochen T1 - ”Ich sehe, was Du hörst!” - Verwendung der Pupillometrie zur Messung des Einflusses kognitiver Belastung auf die Geräuschbewertung T2 - Deutsche Jahrestagung für Akustik (DAGA), Stuttgart Y1 - 2022 CY - Stuttgart ER - TY - GEN A1 - Franz, Jürgen H. T1 - Was ist ein Baum? Eine Kurzgeschichte aus dem Leben des Herrn Schwarzweiß N2 - Herr Schwarzweiß ist seit seiner Geburt nicht in der Lage Farben zu erkennen. Seine Welt ist schwarzweiß. Doch kann er sehr gut zwischen den verschiedenen Grautönen unterscheiden. Für ihn ist Weiß nicht gleich Weiß. Es gibt ein sehr helles Weiß, ein dunkleres Weiß, ein grau unterlegtes Weiß und viele andere Arten von Weiß. ... KW - Kurzgeschichte Y1 - 1995 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-9568 ER - TY - CHAP A1 - Comeron, Adolfo A1 - Kassianov, Evgueni I. A1 - Schäfer, Klaus A1 - Picard, Richard H. A1 - Weber, Konradin T1 - Remote Sensing of Clouds and the Atmosphere XX. Remote Sensing of Clouds and the Atmosphere, Toulouse), 23.-24.09.2015 KW - Luftreinhaltung Y1 - 2015 SN - 978-1-62841-850-7 SN - 0277-786X VL - Proceedings of SPIE ; volume 9640 PB - SPIE CY - Bellingham, Washington, USA ER - TY - JOUR A1 - Naraparaju, R. A1 - Lau, H. A1 - Lange, Martin A1 - Fischer, Christian A1 - Kramer, D. A1 - Schulz, U. A1 - Weber, Konradin T1 - Integrated testing approach using a customized micro turbine for a volcanic ash and CMAS related degradation study of thermal barrier coatings JF - Surface and Coatings Technology KW - Luftreinhaltung Y1 - 2018 U6 - https://doi.org/10.1016/j.surfcoat.2018.01.030 SN - 0257-8972 VL - 337 SP - 198 EP - 208 PB - Elsevier ER - TY - CHAP A1 - Comeron, Adolfo A1 - Jack, James A1 - Kassianov, Evgueni I. A1 - Schäfer, Kiaus A1 - Picard, Richard H A1 - Weber, Konradin T1 - Remote Sensing of Clouds and the Atmosphere XXI Introduction T2 - Remote Sensing of Clouds and the Atmosphere XXI : 28-29 September 2016, Edinburgh, United Kingdom KW - Luftreinhaltung Y1 - 2016 SN - 978-1-5106-0406-3 PB - SPIE CY - Bellingham, Washington, USA ER - TY - JOUR A1 - Queval, Loic A1 - Sotelo, Guilherme G. A1 - Kharmiz, Yassin A1 - Dias, Daniel H. N. A1 - Sass, Felipe A1 - Zermeno, Victor M. R. A1 - Gottkehaskamp, Raimund T1 - Optimization of the Superconducting Linear Magnetic Bearing of a Maglev Vehicle JF - IEEE Transactions on Applied Superconductivity KW - High temperature superconductors KW - linear magnetic bearing KW - maglev system KW - stochastic optimization KW - superconductor modeling Y1 - 2016 U6 - https://doi.org/10.1109/TASC.2016.2528989 SN - 1051-8223 VL - 26 IS - 3 PB - IEEE ER - TY - JOUR A1 - Peters, Christian A1 - H?rten, D. T1 - Sportlandschaft Mallorca. Zur wirtschaftlichen Bedeutung des Radsporttourismus auf der Baleareninsel Mallorca JF - Geographie und Schule Y1 - 2009 SN - 0171-8649 VL - 31 IS - 179 SP - 28 EP - 33 PB - Aulis-Verl. ER - TY - JOUR A1 - Grotkamp, Sabine A1 - Cibis, Wolfgang A1 - Brüggemann, Silke A1 - Coenen, M. Michaela A1 - Gmünder, Hans-Peter A1 - Keller, Klaus A1 - Nüchtern, Elisabeth A1 - Schwegler, Urban A1 - Seger, Wolfgang A1 - Staubli, Stefan A1 - von Raison, B. Bia A1 - Weißmann, R. A1 - Bahemann, A. A1 - Fuchs, H. A1 - Rink, M. A1 - Schian, Marcus A1 - Schmitt, Klaus T1 - Personal Factors of the Bio-Psycho-Social Model (WHO): A Revised Classification by the German Society for Social Medicine and Prevention (DGSMP) JF - Gesundheitswesen KW - FBSK_Webseite Y1 - 2020 U6 - https://doi.org/10.1055/a-1011-3161 VL - 82 IS - 1 SP - 107 EP - 116 PB - Thieme ER - TY - JOUR A1 - Suh, S.-H. A1 - Benim, Ali Cemal T1 - The primitive variables formulation of the Navier-Stokes equations using the finite analytic method JF - Applied Mathematical Modelling KW - Navier-Stokes-Gleichung KW - Finite analytische Methode KW - Numerische Strömungssimulation Y1 - 1989 U6 - https://doi.org/10.1016/0307-904X(89)90066-8 SN - 0307-904X VL - 13 IS - 9 SP - 550 EP - 554 PB - Elsevier ER - TY - JOUR A1 - Benim, Ali Cemal A1 - Neuhoff, H. G. T1 - Analysis of erosion behaviour in a turbocharger radial turbine JF - International Journal for Numerical Methods in Fluids N2 - An analysis of the erosion behaviour of a turbocharger radial turbine is presented. The solution domain includes both sides of the radial turbine scroll with double intake and the rotor channel. In the analysis a dilute gas‐particle flow assumption is employed. The gas turbulence is defined by the k‐ε model. In solving the gas phase equation, the computer code Harwell‐FLOW3D is employed, which is based on a finite volume formulation using non‐orthogonal body‐fitted structured gridding and a pressure correction method. The particle phase is described by a Lagrangian approach, while particle paths are computed deterministically, neglecting the turbulent dispersion. For the computation of particle trajectories the code PTRACK is employed, which has been developed at ABB. Computations are carried out for several particle size classes. The results show that particles are thrown back into the scroll by the rotor at high rates. This seems to be the main source of erosion effects in the scroll. It has been observed that particles are unequally distributed between the scroll sides on their re‐entry, resulting in greater erosion on one of the scroll sides. The maximum erosion along the scroll is found to be likely to occur near the scroll end. KW - Erosion KW - Abgasturbolader KW - Radialturbine Y1 - 1993 U6 - https://doi.org/10.1002/fld.1650160402 SN - 0271-2091 VL - 16 IS - 4 SP - 259 EP - 285 PB - Wiley ER - TY - JOUR A1 - Curcic, Michael A1 - Van Waeyenberge, Bartel A1 - Vansteenkiste, Arne A1 - Weigand, Markus A1 - Sackmann, Vitalij A1 - Stoll, Hermann A1 - Fähnle, Manfred A1 - Tyliszczak, Tolek A1 - Woltersdorf, Georg A1 - Back, Christian H. A1 - Schütz, Gisela T1 - Polarization Selective Magnetic Vortex Dynamics and Core Reversal in Rotating Magnetic Fields JF - Physical Review Letters Y1 - 2008 U6 - https://doi.org/10.1103/PhysRevLett.101.197204 SN - 0031-9007 VL - 101 IS - 19 PB - American Physical Society ER - TY - JOUR A1 - Weigand, Markus A1 - Van Waeyenberge, Bartel A1 - Vansteenkiste, Arne A1 - Curcic, Michael A1 - Sackmann, Vitalij A1 - Stoll, Hermann A1 - Tyliszczak, Tolek A1 - Kaznatcheev, Konstantine A1 - Bertwistle, Drew A1 - Woltersdorf, Georg A1 - Back, Christian H. A1 - Schütz, Gisela T1 - Vortex Core Switching by Coherent Excitation with Single In-Plane Magnetic Field Pulses JF - Physical Review Letters Y1 - 2009 U6 - https://doi.org/10.1103/PhysRevLett.102.077201 SN - 0031-9007 VL - 102 IS - 7 PB - American Physical Society ER - TY - JOUR A1 - Vansteenkiste, A A1 - Weigand, M A1 - Curcic, Michael A1 - Stoll, H A1 - Schütz, G A1 - Van Waeyenberge, B T1 - Chiral symmetry breaking of magnetic vortices by sample roughness JF - New Journal of Physics Y1 - 2009 U6 - https://doi.org/10.1088/1367-2630/11/6/063006 SN - 1367-2630 VL - 11 IS - 6 PB - IOP Publishing ER - TY - JOUR A1 - Kammerer, Matthias A1 - Weigand, Markus A1 - Curcic, Michael A1 - Noske, Matthias A1 - Sproll, Markus A1 - Vansteenkiste, Arne A1 - Van Waeyenberge, Bartel A1 - Stoll, Hermann A1 - Woltersdorf, Georg A1 - Back, Christian H. A1 - Schuetz, Gisela T1 - Magnetic vortex core reversal by excitation of spin waves JF - Nature Communications Y1 - 2011 U6 - https://doi.org/10.1038/ncomms1277 SN - 2041-1723 VL - 2 IS - 1 PB - Springer Nature ER - TY - CHAP A1 - Weber, Konradin A1 - Reichardt, R. A1 - Fischer, Christian A1 - Moser, H. M. A1 - Eliasson, Jonas ED - Jha, Manoj K. ED - Lazard, Myriam ED - Zaharim, Azami ED - Sopian, Kamaruzzaman T1 - Computational Visualization of Volcanic Ash Plume Concentrations Measured by light Aircrafts over Germany and Iceland during the Recent Eruptions of the Volcanoes Eyjafjallajökull and Grimsvötn T2 - Recent advances in Fluid Mechanics, Heat & Mass Transfer, Biology and Ecology KW - Luftreinhaltung KW - Vulkanasche KW - Visualisierung KW - Eyjafjallajökull KW - Atmosphärisches Aerosol Y1 - 2012 SN - 978-1-61804-065-7 SP - 236 EP - 240 PB - WSEAS ER - TY - CHAP A1 - Deniz Canal, Cansu A1 - Diederich, Michael A1 - Karacay, Onur A1 - Benim, Ali Cemal A1 - Hamberger, Andreas A1 - Heese, Markus A1 - Schräder, K. H. ED - Sharma, Rajesh Kumar ED - Srivastava, Shailesh Kumar ED - Benim, Ali Cemal T1 - Investigation of Boiler Efficiency Improvements via Enthalpy Wheel with Application to a Biomass Boiler T2 - Mathematical Theory and Simulation of Scientific Problems: FIAM-2023, Dubai, UAE, December 21–22 KW - Numerische Strömungssimulation KW - Wärmeaustauscher KW - Boiler KW - Bioenergieerzeugung KW - Biomasse Y1 - 2025 SN - 9789819625789 U6 - https://doi.org/10.1007/978-981-96-2579-6_13 SN - 2194-1009 VL - Springer Proceedings in Mathematics & Statistics, Bd. 487 SP - 189 EP - 200 PB - Springer Nature CY - Singapore ER - TY - JOUR A1 - Uffmann, Kai A1 - Abicht, Claus A1 - Grote, Wolfgang A1 - Quick, Harald H. A1 - Ladd, Mark E. T1 - Design of an MR-compatible piezoelectric actuator for MR elastography JF - Concepts in Magnetic Resonance Part A: Bridging Education and Research N2 - Magnetic Resonance (MR) elastography is a method for measuring tissue elasticity via phase images acquired with an MR scanner. The propagation of periodic mechanical waves through the tissue can be captured by means of a modified phase contrast sequence. These waves are generated with a mechanical oscillator (actuator) and coupled into the tissue through the skin. The actuator must be capable of generating a sinusoidal excitation with excellent phase and amplitude stability, while not disturbing the MR imaging process. In this work, an actuator based on a piezoelectric principle was developed. Based on the imaging evaluation of several material samples, the housing for the piezoelectric ceramic was constructed of aluminum. Smaller parts of the housing were manufactured from brass and titanium to fulfill the mechanical constraints. A lever was used to transfer the oscillation generated by the piezoelectric ceramic to the point of excitation. The lever amplifies the piezoelectric motion, allowing for a more compact design. Three different lever designs were characterized by an acceleration sensor both outside and inside the magnet. It was shown that the rigidity of the lever, as determined by its material and form, was decisive in determining the resonant frequency of the system and therefore the maximum practical frequency of operation. It was also shown that the motion of the oscillator is unaffected by the electromagnetic fields of the MR imager. The final design can be placed directly in the magnet bore within a few centimeters of the tissue volume to be imaged without generating significant artifacts. An amplitude range of 0–1 mm in the frequency range from 0 to over 300 Hz was achieved, sufficient for performing most MR elastography applications. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 239–254, 2002 KW - Elasticity KW - Elastography KW - Actuator KW - MRI KW - Piezoelectric Y1 - 2002 UR - 1552-5023 U6 - https://doi.org/https://doi.org/10.1002/cmr.10045 VL - 15 IS - 4 SP - 239 EP - 254 PB - Wiley ER - TY - JOUR A1 - Hechler, T. A1 - Kosfelder, J. A1 - Denecke, H. A1 - Dobe, M. A1 - Hübner, B. A1 - Martin, A. A1 - Menke, A. A1 - Schroeder, S. A1 - Marbach, S. A1 - Zernikow, B. T1 - Pain-related coping strategies in children and adolescents with chronic pain. Validation of a German version of the Paediatric Pain Coping Inventory (PPCI revised) JF - Der Schmerz KW - FBSK_Webseite Y1 - 2008 U6 - https://doi.org/10.1007/s00482-008-0621-4 N1 - © Deutsche Gesellschaftzum Studium des Schmerzes. Published by Springer Medizin Verlag - all rights reserved 2008 VL - 22 IS - 4 SP - 442 EP - 457 PB - Springer ER - TY - JOUR A1 - Hübner, B. A1 - Hechler, T. A1 - Dobe, M. A1 - Damschen, U. A1 - Kosfelder, Joachim A1 - Denecke, H. A1 - Schroeder, S. A1 - Zernikow, B. T1 - Pain-related disability in adolescents suffering from chronic pain. Preliminary examination of the Pediatric Pain Disability Index (P-PDI) JF - Der Schmerz KW - FBSK_Webseite Y1 - 2009 UR - http://www.ncbi.nlm.nih.gov/pubmed/18941801 U6 - https://doi.org/10.1007/s00482-008-0730-0 N1 - © Deutsche Gesellschaftzum Studium des Schmerzes. Published by Springer Medizin Verlag - all rights reserved 2008 VL - 23 IS - 1 SP - 20 EP - 32 PB - Springer ER - TY - JOUR A1 - Wager, J. A1 - Tietze, A-L A1 - Denecke, H. A1 - Schroeder, S. A1 - Vocks, S. A1 - Kosfelder, Joachim A1 - Zernikow, B. A1 - Hechler, T. T1 - Pain perception of adolescents with chronic functional pain : adaptation and psychometric validation of the Pain Perception Scale (SES) by Geissner JF - Der Schmerz KW - FBSK_Webseite Y1 - 2010 U6 - https://doi.org/10.1007/s00482-010-0920-4 N1 - © Deutsche Gesellschaftzum Studium des Schmerzes. Published by Springer Medizin Verlag - all rightsreserved 2008 VL - 24 IS - 3 SP - 236 EP - 250 PB - Springer ER - TY - CHAP A1 - Vogel, Andreas A1 - Weber, Konradin A1 - Eliasson, Jonas A1 - Palsson, Asgeir A1 - Moser, H. M. A1 - Palsson, Thorgeir A1 - von Löwis, S. A1 - Fischer, Christian T1 - Airborne and groundbased measurements of ash particles on Iceland and over Germany during the Grímsvötn eruption May 2011 [Abstract] T2 - Geophysical Research Abstracts:EGU General Assembly 2012, held 22-27 April, 2012 in Vienna, Austria N2 - The eruption of the Grimsvötn volcano in May 2010 posed with its ash plume a thread to the aviation in northern Europe. Because of ash plume forecasts of the VAAC London the airport of Keflavik in Iceland as well as airports in England, Scotland and Scandinavia were closed for some time, which caused the cancellation or change of about 500 flights in Europe. Even in Germany the airports of Bremen, Hamburg and Berlin were closed for several hours on 25 May 2011. During this eruption period in May 2011, a team of the Duesseldorf University of Applied Sciences, the University of Iceland, the University of Reykjavik and the IMO has performed airborne in-situ measurements over Iceland and Germany as well as ground based measurements in the south of Iceland. The ground based measurements were performed continuously during the whole eruption period at two significant positions (Skogar and Hvollsvöllur) with optical particle counters (OPCs). The measurement method was based on measuring the airborne concentrations of the classic aerosol components (PM10, PM2.5 and PM1) and TSP (total suspended particles) every 6 seconds. Additional measurement flights on Iceland were started already one day after the beginning of the eruption (twelve in-situ measurement flights) and marked the spatial and temporal spread of volcanic ash in the atmosphere. For the flights light slow flying piston engine powered airplanes where used. The flights over Iceland focused on the western part of Iceland in the region of Reykjavik and Keflavik and over the international airport in Keflavik and were mostly coordinated by ISAVIA. The measurement flights helped to keep Keflavik International Airport open for many additional hours despite of adverse predictions by the London VAAC model, because it was possible to observe the particle concentration on-line during the flights. In Germany a measurement flight was performed on 25 May 2012 over the northern part of Germany where the volcanic ash cloud was forecasted from the dispersion model of the London VAAC. This flight was performed on the behalf of the German Weather Service (DWD). The measurement flights revealed most time relative low airborne ash concentrations over western Iceland, although the groundbased measured ash concentrations in the south of Iceland nearer to the Grimsvötn were very high. In Germany the measured concentrations during the flight were low enough to be consistent with the re-opening of the airports Bremen, Hamburg and Berlin, which were closed by the authorities for several hours on 25 May 2011 because of high concentration predictions by the VAAC-model. The measurement flights clearly proved that OPCs, based on slow flying piston-motor driven aircrafts, are very suitable for the determination of airborne ash particles during volcanic eruptions. This is an important issue for air traffic safety. KW - Luftreinhaltung Y1 - 2012 UR - https://meetingorganizer.copernicus.org/EGU2012/EGU2012-12854-1.pdf SP - 12854 PB - Copernicus CY - Göttingen 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 - JOUR A1 - Nehr, Sascha A1 - Bohn, Birger A1 - Dorn, Hans-Peter A1 - Fuchs, H. A1 - Häseler, R. A1 - Hofzumahaus, A. A1 - Li, X. A1 - Rohrer, F. A1 - Tillmann, R. A1 - Wahner, A. T1 - Atmospheric photochemistry of aromatic hydrocarbons: OH budgets during SAPHIR chamber experiments JF - Atmospheric Chemistry and Physics N2 - Abstract. Current photochemical models developed to simulate the atmospheric degradation of aromatic hydrocarbons tend to underestimate OH radical concentrations. In order to analyse OH budgets, we performed experiments with benzene, toluene, p-xylene and 1,3,5-trimethylbenzene in the atmosphere simulation chamber SAPHIR. Experiments were conducted under low-NO conditions (typically 0.1–0.2 ppb) and high-NO conditions (typically 7–8 ppb), and starting concentrations of 6–250 ppb of aromatics, dependent on OH rate constants. For the OH budget analysis a steady-state approach was applied in which OH production and destruction rates (POH and DOH) have to be equal. The POH were determined from measurements of HO2, NO, HONO, and O3 concentrations, considering OH formation by photolysis and recycling from HO2. The DOH were calculated from measurements of the OH concentrations and total OH reactivities. The OH budgets were determined from DOH/POH ratios. The accuracy and reproducibility of the approach were assessed in several experiments using CO as a reference compound where an average ratio DOH/POH = 1.13 ± 0.19 was obtained. In experiments with aromatics, these ratios ranged within 1.1–1.6 under low-NO conditions and 0.9–1.2 under high-NO conditions. The results indicate that OH budgets during photo-oxidation experiments with aromatics are balanced within experimental accuracies. Inclusion of a further, recently proposed OH production via HO2 + RO2 reactions led to improvements under low-NO conditions but the differences were small and insignificant within the experimental errors. KW - Luftreinhaltung Y1 - 2014 U6 - https://doi.org/10.5194/acp-14-6941-2014 SN - 1680-7324 VL - 14 IS - 13 SP - 6941 EP - 6952 PB - Copernicus 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 - Zellner, R. A1 - Herrmann, H. A1 - Wiesen, P. A1 - Nehr, Sascha T1 - New and Emerging Technologies of Societal Relevance: Impact on Air Quality and Climate JF - Chemie Ingenieur Technik KW - Luftreinhaltung Y1 - 2016 U6 - https://doi.org/10.1002/cite.201650083 SN - 0009-286X VL - 88 IS - 9 SP - 1257 EP - 1258 PB - Wiley 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 - CHAP A1 - Nehr, Sascha A1 - Baus, Lukas A1 - Çınar, H. T1 - Lüftung in Bildungseinrichtungen, 29. Oktober 2025, Köln T2 - 2. Kölner Innenraum-Forum KW - Luftreinhaltung Y1 - 2025 UR - https://www.researchgate.net/publication/397427753_Luftung_in_Bildungseinrichtungen PB - HYGIUM – Zentrum für Hygiene und Umweltmedizin GmbH ER - TY - JOUR A1 - Niemann, Jörg A1 - Basson, A. A1 - Fussenecker, Claudia A1 - Kruger, K. A1 - Schlösser, M. A1 - Turek, S. A1 - Amarnath, H. Umadevi T1 - Implementation of Eye-Tracking Technology in Holonic Manufacturing Systems JF - Procedia - Social and Behavioral Sciences Y1 - 2018 U6 - https://doi.org/10.1016/j.sbspro.2018.03.005 VL - 238 SP - 37 EP - 45 PB - Elsevier ET - SIM 2017: 14th International Symposium in Management, Challenges and Innovation in Management and Entrepreneurship} ER - TY - CHAP A1 - Fomin, A.S. A1 - Kiselev, S.V. A1 - Jahr, Andreas A1 - Sim, H. T1 - Development of the Kinematic Model of Horizontal-Set Drive for Blades of Combine Harvester Thresher T2 - Materialien zum wissenschaftlichen Seminar der Stipendiaten der Programme «Michail Lomonosov» und «Immanuel Kant» 2015/2016 Y1 - 2017 IS - 12 SP - 188 EP - 196 ER - TY - CHAP A1 - Jahr, Andreas A1 - Sim, H. A1 - Batos, Andrej A1 - Molla, G. A1 - Berk, V. A1 - Villena Martínez, J. D. T1 - A novel method to examine the abrasive and impact stress behavior of agricultural blades T2 - VII Congreso Ibérico de Agroingeniería y Ciencias Hortícolas: innovar y producir para el futuro. Libro de actas N2 - Cutting of stalk material is a core process within the whole harvesting period. During the entire harvesting, every stalk is cut at least one time. For other agricultural processes, such as grain crop harvesting or mulching of brownfields, cutting processes belong also to the main techniques. They have a significant influence on the efficiency and profitability of agricultural machines. Minimizing wear has a high level of importance regarding an environmental friendly and resource efficient agriculture. Wear during agricultural cutting processes is mainly caused due to abrasion and impact stress. Blunt and deformed blades affect the energy efficiency and the cutting quality. The increase of fuel consumption and frequent machine breakdowns with an involvement of high labor and material costs generate considerable economic losses. A consequent, methodical optimization of the wear behavior of the blades can offer a high saving potential of ecological and economic resources. The blade geometry, base material and heat respectively surface treatment substantially determine the wear resistance. Under technological and economic considerations these parameters have to be optimized. Therefore, a test method has been developed at the FMDauto in cooperation with the Ennepetaler Schneid- und Mähtechnik (ESM) GmbH & Co KG. The test bench enables to test different blades of agricultural machines under standardized and repeatable conditions. This paper presents the test bench and the results of several wear tests. The examinations of the abrasive wear and the impact stress on cutter blades are shown. Algorithms developed at FMDauto are used to analyze the results. It is carried out that further developments of the analyzing methods to describe the sharpness and disruptions of cutter blades are reasonable. Y1 - 2014 SN - 978-84-695-9055-3 SP - 854 EP - 859 ER - TY - CHAP A1 - Dörner, Ralf A1 - Tesch, Alexander A1 - Rüggeberg, Jim A1 - Fuchs, Andreas A1 - Grimm, Paul A1 - Hillig, Julian A1 - Pfeiffer, Thies A1 - Blattgerste, Jonas A1 - Bernloehr, Annette A1 - Vogel, Kristina A1 - Bauer, Nicola H. A1 - Pestov, Alec A1 - Spierling, Ulrike A1 - Geiger, Christian A1 - Hildebrand, Axel A1 - Tropper, Tobias A1 - Wilke, Wilhelm A1 - Winkler, Christian A1 - Makled, Elhassan A1 - Schott, Ephraim A1 - Broll, Wolfgang A1 - Weidner, Florian A1 - Fröhlich, Bernd A1 - Göbel, Gunther A1 - Steinhauser, Marco A1 - Schwandt, Tobias A1 - Kumari, Gunjan A1 - Stolz, Georg A1 - Werner, Stephan A1 - Uzun, Yücel A1 - Oppermann, Leif ED - Dörner, Ralf ED - Broll, Wolfgang ED - Grimm, Paul ED - Jung, Bernhard T1 - Fallbeispiele für VR/AR T2 - Virtual und Augmented Reality (VR/AR): Grundlagen und Methoden von Extended Realities (XR) KW - Virtuelle Realität Y1 - 2026 SN - 9783662723081 U6 - https://doi.org/10.1007/978-3-662-72309-8_11 SP - 579 EP - 628 PB - Springer Nature CY - Berlin, Heidelberg ER -