@article{KrebsMuellerBraun2021, author = {Krebs, Christian and M{\"u}ller, Patrick and Braun, Alexander}, title = {Impact of Windshield Optical Aberrations on Visual Range Camera Based Classification Tasks Performed by CNNs}, series = {London Imaging Meeting}, volume = {2021}, journal = {London Imaging Meeting}, number = {1}, publisher = {Ingenta connect}, isbn = {0-89208-346-6}, issn = {2694-118X}, doi = {10.2352/issn.2694-118X.2021.LIM-83}, pages = {83 -- 87}, year = {2021}, language = {de} } @article{MillardSorivelleDeljaninetal.2018, author = {Millard, Jeremy and Sorivelle, Marie and Deljanin, Sarah and Unterfrauner, Elisabeth and Voigt, Christian}, title = {Is the Maker Movement Contributing to Sustainability?}, series = {Sustainability}, volume = {10}, journal = {Sustainability}, number = {7}, publisher = {MDPI}, issn = {2071-1050}, doi = {10.3390/su10072212}, pages = {2212}, year = {2018}, language = {en} } @article{SeebacherVanaVoigtetal.2021, author = {Seebacher, Lisa M. and Vana, Irina and Voigt, Christian and Tschank, Juliet}, title = {Is Science for Everyone? Exploring Intersectional Inequalities in Connecting With Science}, series = {Frontiers in Education}, volume = {6}, journal = {Frontiers in Education}, publisher = {Frontiers}, issn = {2504-284X}, doi = {10.3389/feduc.2021.673850}, year = {2021}, language = {en} } @article{KernebeckHollePogschebaetal.2019, author = {Kernebeck, Sven and Holle, Daniela and Pogscheba, Patrick and Jordan, Felix and Mertl, Fabian and Huldtgren, Alina and Bader, Sebastian and Kirste, Thomas and Teipel, Stefan and Holle, Bernhard and Halek, Margareta}, title = {A Tablet App- and Sensor-Based Assistive Technology Intervention for Informal Caregivers to Manage the Challenging Behavior of People With Dementia (the insideDEM Study): Protocol for a Feasibility Study}, series = {JMIR research protocols}, volume = {8}, journal = {JMIR research protocols}, number = {2}, publisher = {JMIR}, doi = {10.2196/11630}, year = {2019}, language = {en} } @article{MoellmannHungerDusendetal.2019, author = {M{\"o}llmann, Anne and Hunger, Antje and Dusend, Christina and van den Hout, Marcel and Buhlmann, Ulrike}, title = {Gazing at facial features increases dissociation and decreases attractiveness ratings in non-clinical females - A potential explanation for a common ritual in body dysmorphic disorder}, series = {PloS one}, volume = {14}, journal = {PloS one}, number = {7}, publisher = {PLoS}, organization = {PLoS}, doi = {10.1371/journal.pone.0219791}, year = {2019}, abstract = {Rituals, such as gazing at faces, are common in body dysmorphic disorder (BDD) and appear in cognitive-behavioral models as a maintaining factor. Rituals are also common in obsessive-compulsive disorder (OCD). In contrast to OCD, the proposed associations between rituals and intrusive thoughts/appearance preoccupation have not been empirically investigated for BDD. We examined if the assumed effect of gazing rituals on attractiveness ratings exists and if it is associated with dissociation. In an experiment, we asked N = 65 non-clinical females to focus on the nose of a photographed face at pre- and post-test. In between, participants gazed at the nose of either the same (relevant gazing) or another face (irrelevant gazing). We found increasing dissociation after gazing in both conditions and a differentially stronger decrease of attractiveness ratings in the relevant gazing condition. Our findings support the hypothesized effect of gazing rituals on attractiveness evaluation in cognitive-behavioral models for BDD.}, language = {en} } @article{Langmann2010, author = {Langmann, Reinhard}, title = {Distributed Web-Based Control System}, series = {International Journal of Online Engineering (iJOE)}, volume = {6}, journal = {International Journal of Online Engineering (iJOE)}, number = {3}, publisher = {iJOE}, doi = {10.3991/ijoe.v6i3.1345}, year = {2010}, language = {en} } @article{BhattacharyyaChattopadhyayBanerjeeetal.2018, author = {Bhattacharyya, Suvanjan and Chattopadhyay, Himadri and Banerjee, Arnab and Benim, Ali Cemal}, title = {Heat transfer and flow field in a circular twisted channel}, series = {MATEC Web of Conferences}, volume = {240}, journal = {MATEC Web of Conferences}, publisher = {edp sciences}, doi = {10.1051/matecconf/201824001005}, year = {2018}, language = {en} } @article{PrataDezitterDaviesetal.2016, author = {Prata, A. J. and Dezitter, F. and Davies, I. and Weber, Konradin and Birnfeld, M. and Moriano, D. and Bernardo, C. and Vogel, A. and Prata, G. S. and Mather, T. A. and Thomas, H. E. and Cammas, J. and Weber, M.}, title = {Artificial cloud test confirms volcanic ash detection using infrared spectral imaging}, series = {Scientific reports}, volume = {6}, journal = {Scientific reports}, publisher = {Springer Nature}, doi = {10.1038/srep25620}, year = {2016}, abstract = {Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 μm) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallaj{\"o}kull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii ~10 μm) collected from Iceland immediately after the Eyjafjallaj{\"o}kull eruption and had a vertical thickness of ~200 m, a width of ~2 km and length of between 2 and 12 km. Concentrations of ~200 μg m(-3) were identified by AVOID at distances from ~20 km to ~70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft.}, language = {en} } @article{BonkLauxRoedderetal.2017, author = {Bonk, Christian Dirk and Laux, Christoph and R{\"o}dder, Maximilian and Neef, Matthias}, title = {Design of a 1 KW Organic Rankine Cycle for Teaching and Research Issues}, series = {Energy Procedia}, volume = {129}, journal = {Energy Procedia}, publisher = {Elsevier}, doi = {10.1016/j.egypro.2017.09.117}, pages = {931 -- 938}, year = {2017}, abstract = {This paper deals with the design of a micro-scale ORC plant for teaching and research including the development of an automated control concept. The aim is to provide a safe and environmentally acceptable micro-scale heat engine, which can be developed, implemented and used in university labs for the education of students as well as for small research projects. The test rig allows the support of several learning outcomes on a multi-disciplinary level particularly for the implementation and simulation of small power systems. Special attention was given to the organic working fluid characteristics and its selection process. In addition to the above-mentioned performance goals, favourable safety properties and low global warming potential were decisive in the selection of the novel organic fluid called 3M™ Novec™ 649. The performance and the fluid behaviour of Novec 649 in a micro-scale power cycle are of major interest and the research goal for the test rig presented in this paper. Due to the expected power output of 1 kW, a scroll expander was chosen as the generator drive for the micro plant. In order to design the major parts of the ORC, the thermodynamic simulation software EBSILON®Professional was used. The supply temperature was set to 140 °C. As a result of the simulation, feasible expander inlet pressures spread from 5.5 bar to 8.5 bar. This leads to thermal efficiencies of the ORC in the order of 5 \%. Adding a recuperator to the cycle system decreases the operating pressure range but in the end, the thermal efficiency can be increased by 1.5 \%-points up to 6.2 \%. Finally, an automated control concept is introduced, where the pump is controlled via the fill level measurement system.}, language = {en} } @article{ElversSteffens2017, author = {Elvers, Paul and Steffens, Jochen}, title = {The Sound of Success: Investigating Cognitive and Behavioral Effects of Motivational Music in Sports}, series = {Frontiers in psychology}, volume = {8}, journal = {Frontiers in psychology}, publisher = {Frontiers}, doi = {10.3389/fpsyg.2017.02026}, year = {2017}, abstract = {Listening to music before, during, or after sports is a common phenomenon, yet its functions and effects on performance, cognition, and behavior remain to be investigated. Listening to music before, during, or after sports is a common phenomenon, yet its functions and effects on performance, cognition, and behavior remain to be investigated. In this study we present a novel approach to the role of music in sports and exercise that focuses on the notion of musical self-enhancement (Elvers, 2016). We derived the following hypotheses from this framework: listening to motivational music will (i) enhance self-evaluative cognition, (ii) improve performance in a ball game, and (iii) evoke greater risk-taking behavior. To evaluate the hypotheses, we conducted a between-groups experiment (N = 150) testing the effectiveness of both an experimenter playlist and a participant-selected playlist in comparison to a no-music control condition. All participants performed a ball-throwing task developed by Decharms and Dav{\´e} (1965), consisting of two parts: First, participants threw the ball from fixed distances into a funnel basket. During this task, performance was measured. In the second part, the participants themselves chose distances from the basket, which allowed their risk-taking behavior to be assessed. The results indicate that listening to motivational music led to greater risk taking but did not improve ball-throwing performance. This effect was more pronounced in male participants and among those who listened to their own playlists. Furthermore, self-selected music enhanced state self-esteem in participants who were performing well but not in those who were performing poorly. We also discuss further implications for the notion of musical self-enhancement. // Listening to music before, during, or after sports is a common phenomenon, yet its functions and effects on performance, cognition, and behavior remain to be investigated. In this study we present a novel approach to the role of music in sports and exercise that focuses on the notion of musical self-enhancement (Elvers, 2016). We derived the following hypotheses from this framework: listening to motivational music will (i) enhance self-evaluative cognition, (ii) improve performance in a ball game, and (iii) evoke greater risk-taking behavior. To evaluate the hypotheses, we conducted a between-groups experiment (N = 150) testing the effectiveness of both an experimenter playlist and a participant-selected playlist in comparison to a no-music control condition. All participants performed a ball-throwing task developed by Decharms and Dav{\´e} (1965), consisting of two parts: First, participants threw the ball from fixed distances into a funnel basket. During this task, performance was measured. In the second part, the participants themselves chose distances from the basket, which allowed their risk-taking behavior to be assessed. The results indicate that listening to motivational music led to greater risk taking but did not improve ball-throwing performance. This effect was more pronounced in male participants and among those who listened to their own playlists. Furthermore, self-selected music enhanced state self-esteem in participants who were performing well but not in those who were performing poorly. We also discuss further implications for the notion of musical self-enhancement.}, language = {en} } @article{GrebSteffensSchlotz2019, author = {Greb, Fabian and Steffens, Jochen and Schlotz, Wolff}, title = {Modeling Music-Selection Behavior in Everyday Life: A Multilevel Statistical Learning Approach and Mediation Analysis of Experience Sampling Data}, series = {Frontiers in psychology}, volume = {10}, journal = {Frontiers in psychology}, publisher = {Frontiers}, doi = {10.3389/fpsyg.2019.00390}, year = {2019}, abstract = {Music listening has become a highly individualized activity with smartphones and music streaming services providing listeners with absolute freedom to listen to any kind of music in any situation. Until now, little has been written about the processes underlying the selection of music in daily life. The present study aimed to disentangle some of the complex processes among the listener, situation, and functions of music listening involved in music selection. Utilizing the experience sampling method, data were collected from 119 participants using a smartphone application. For 10 consecutive days, participants received 14 prompts using stratified-random sampling throughout the day and reported on their music-listening behavior. Statistical learning procedures on multilevel regression models and multilevel structural equation modeling were used to determine the most important predictors and analyze mediation processes between person, situation, functions of listening, and music selection. Results revealed that the features of music selected in daily life were predominantly determined by situational characteristics, whereas consistent individual differences were of minor importance. Functions of music listening were found to act as a mediator between characteristics of the situation and music-selection behavior. We further observed several significant random effects, which indicated that individuals differed in how situational variables affected their music selection behavior. Our findings suggest a need to shift the focus of music-listening research from individual differences to situational influences, including potential person-situation interactions.}, language = {en} } @book{BleckSchultzConenetal.2020, author = {Bleck, Christian and Schultz, Laura and Conen, Ina and Frerk, Timm and Henke, Stefanie and Leiber, Simone and Fuchs, Harry}, title = {Selbstbestimmt teilhaben in Altenpflegeeinrichtungen}, publisher = {Nomos}, address = {Baden-Baden}, isbn = {9783748907664}, doi = {10.5771/9783748907664}, year = {2020}, language = {de} } @article{SenthurAnandRameshKumaretal.2022, author = {Senthur, N.S. and Anand, C and Ramesh Kumar, M and Elumalai, P.V. and Shajahan, Mohamed Iqbal and Benim, Ali Cemal and Nasr, Emad Abouel and Hussein, H.M.A. and Parthasarathy, M.}, title = {Influence of cobalt chromium nanoparticles in homogeneous charge compression ignition engine operated with citronella oil}, series = {Energy Science \& Engineering}, volume = {10}, journal = {Energy Science \& Engineering}, number = {4}, publisher = {Wiley}, issn = {2050-0505}, doi = {10.1002/ese3.1088}, pages = {1251 -- 1263}, year = {2022}, language = {en} } @incollection{BuettnerRuempelHobohm2011, author = {B{\"u}ttner, Stephan and R{\"u}mpel, Stefanie and Hobohm, Hans-Christoph}, title = {Informationswissenschaftler im Forschungsdatenmanagement}, series = {Handbuch Forschungsdatenmanagement}, booktitle = {Handbuch Forschungsdatenmanagement}, editor = {M{\"u}ller, Lars and B{\"u}ttner, Stephan and Hobohm, Hans-Christoph}, publisher = {Bock u. Herchen}, address = {Bad Honnef}, isbn = {978-3-88347-283-6}, pages = {203 -- 218}, year = {2011}, abstract = {Seit den ersten nationalen, strategischen Papieren zu Datenmanagement-Fragen in der Wissenschaft in den USA (NSF, 2005), Großbritannien (Lyon, 2007; Swan \& Brown, 2008), der EU (Atkinson et al. 2008; OGF22-ET CG, 2008) und vor allem seit den Guidelines der OECD (2007) wird international intensiv {\"u}ber die Erfordernisse der Ausbildung von „Datenspezialisten" diskutiert. Grundlegende {\"U}berlegungen, die einen gewissen internationalen Konsens gefunden haben, wurden im Auftrag von JISC von Swan und Brown (2008, S. 1) entwickelt (vgl. Hank \& Davidson, 2009). Sie schlagen vier Rollen im Forschungsdatenmanagement vor. Neben dem Data Creator (datenproduzierender Forscher), dem Data Scientist (Wissenschaftler der bspw. bei der Datenanalyse unterst{\"u}tzt) und dem Data Manager (verantwortlich f{\"u}r alle technischen Aspekte: Lagerung, Zugriff, Aufbewahrung) wurde auch der Data Librarian benannt. Im Weiteren wird, auch unter Beachtung der T{\"a}tigkeiten die im Data Curation Lifecycle Model (s. Beitrag von R{\"u}mpel. Kap. 1.2) aufgef{\"u}hrt sind, neben dem Data Manager und dem Data Curator insbesondere auf den Data Librarian eingegangen.}, language = {de} } @incollection{RuempelBuettner2011, author = {R{\"u}mpel, Stefanie and B{\"u}ttner, Stephan}, title = {Bibliotheken und Bibliothekare im Forschungsdatenmanagement}, series = {Digitale Wissenschaft}, booktitle = {Digitale Wissenschaft}, editor = {Schomburg, Silke and Leggewie, Claus and Lobin, Henning and Puschmann, Cornelius}, publisher = {hbz}, address = {K{\"o}ln}, pages = {107 -- 114}, year = {2011}, subject = {Forschungsdaten}, language = {de} } @incollection{FranzSpatschekvanRiessen2024, author = {Franz, Julia and Spatschek, Christian and van Rießen, Anne}, title = {Fachkr{\"a}ftemangel und De-Professionalisierung in der Sozialen Arbeit - Ausgangspunkte und leitende Fragestellungen}, series = {Fachkr{\"a}ftemangel und De-Professionalisierung in der Sozialen Arbeit: Analysen, Bearbeitungsweisen und Handlungsstrategien}, booktitle = {Fachkr{\"a}ftemangel und De-Professionalisierung in der Sozialen Arbeit: Analysen, Bearbeitungsweisen und Handlungsstrategien}, editor = {Franz, Julia and Spatschek, Christian and van Rießen, Anne}, publisher = {Barbara Budrich}, address = {Opladen, Berlin, Toronto}, isbn = {978-3-8474-1994-5}, doi = {10.3224/84743060}, pages = {11 -- 17}, year = {2024}, subject = {Sozialarbeit}, language = {de} } @article{WolfThielbeerUlrichetal.2024, author = {Wolf, Dominik Werner and Thielbeer, Boris and Ulrich, Markus and Braun, Alexander}, title = {Wavefront aberration measurements based on the Background Oriented Schlieren method}, series = {Measurement: Sensors}, journal = {Measurement: Sensors}, publisher = {Elsevier}, issn = {2665-9174}, doi = {10.1016/j.measen.2024.101509}, year = {2024}, abstract = {Applications based on neural networks tend to be very sensitive to dataset shifts. Hence, the perception chain for autonomous driving is safeguarded against perturbations by imposing exaggerated optical quality requirements. Due to the non-linear coupling of optical elements, system requirements of camera-based Advanced Driver Assistance Systems (ADAS) can not be easily decomposed into individual part tolerances of the objective lens and the windscreen. This holds true for intensity-based part measurements, e.g. slanted edge measurements according to ISO12233, which can fundamentally not capture interference effects of the complex light field. Instead wavefront-based part measurements are required. Unfortunately, state-of-the-art wavefront measurement techniques are limited by the spanned sensitive area of the Shack-Hartmann lenslet array or the aperture stop of a corresponding interferometrical setup, respectively. Further, both measurements are limited by using collimated light only, whereas the target application has a large (angular) field of view, requiring many different measurements. We address those bottlenecks by proposing a novel wavefront aberration measurement procedure based on the Background Oriented Schlieren (BOS) method utilizing image auto-correlation. We analytically derive the governing equations for determining the Zernike coefficients of a wavefront aberration map in the knowledge of the local refractive power map obtained by a high-resolution BOS measurement. Furthermore, we experimentally demonstrate the feasibility of the measurement technique. Applying this novel method yields the promise of affordable wavefront aberration measurements only requiring a high-resolution camera and a sophisticated alignment strategy.}, language = {en} } @article{LangmannMichael2019, author = {Langmann, Reinhard and Michael, Stiller}, title = {The PLC as a Smart Service in Industry 4.0 Production System}, series = {Applied Sciences}, volume = {9}, journal = {Applied Sciences}, number = {18}, publisher = {MDPI}, issn = {2076-3417}, doi = {10.3390/app9183815}, year = {2019}, language = {en} } @article{KammererWeigandCurcicetal.2011, author = {Kammerer, Matthias and Weigand, Markus and Curcic, Michael and Noske, Matthias and Sproll, Markus and Vansteenkiste, Arne and Van Waeyenberge, Bartel and Stoll, Hermann and Woltersdorf, Georg and Back, Christian H. and Schuetz, Gisela}, title = {Magnetic vortex core reversal by excitation of spin waves}, series = {Nature Communications}, volume = {2}, journal = {Nature Communications}, number = {1}, publisher = {Springer Nature}, issn = {2041-1723}, doi = {10.1038/ncomms1277}, year = {2011}, language = {en} } @incollection{KrieterBreiter2020, author = {Krieter, Philipp and Breiter, Andreas}, title = {Digitale Spuren von Studierenden in virtuellen Lernumgebungen}, series = {Studierende - Medien - Universit{\"a}t: Einblicke in studentische Medienwelt}, booktitle = {Studierende - Medien - Universit{\"a}t: Einblicke in studentische Medienwelt}, editor = {Hofhues, Sandra and Schiefner-Rohs, Mandy and Aßmann, Sandra and Brahm, Taiga}, publisher = {Waxmann}, address = {M{\"u}nster}, isbn = {9783830940494}, doi = {10.31244/9783830990499}, pages = {131 -- 152}, year = {2020}, abstract = {In diesem Beitrag werden die Ergebnisse und der Prozess der LogfileAnalyse im Projekt You(r) Study beschrieben, die zum Ziel hat, die qualitativen Daten des Projekts mit den quantitativen Logdaten eines Learning Management Systems zu verbinden. Mittels deskriptiver Methoden und Clusterbildung werden die Logdaten in Hinblick auf die Fragestellungen des Projekts betrachtet. Außerdem wird kritisch diskutiert, welche Grenzen eine Logfile-Analyse in Bezug zur Zielsetzung hat}, subject = {moodle}, language = {de} } @inproceedings{KrieterBreiter2018, author = {Krieter, Philipp and Breiter, Andreas}, title = {Track every move of your students: log files for Learning Analytics from mobile screen recordings}, series = {DeLFI 2018: die 16. E-Learning Fachtagung Informatik der Gesellschaft f{\"u}r Informatik e.V., 10.-12. September 2018, Frankfurt am Main, Deutschland}, volume = {Lecture Notes in Informatics(LNI)-Proceedings, Vol. P-284}, booktitle = {DeLFI 2018: die 16. E-Learning Fachtagung Informatik der Gesellschaft f{\"u}r Informatik e.V., 10.-12. September 2018, Frankfurt am Main, Deutschland}, editor = {Kr{\"o}mker, Detlef and Schroeder, Ulrik}, publisher = {K{\"o}llen Druck+Verlag}, address = {Bonn}, organization = {Gesellschaft f{\"u}r Informatik, Bonn}, isbn = {9783885796787}, doi = {10.18154/RWTH-2018-229913}, pages = {231 -- 242}, year = {2018}, abstract = {One of the main data sources for Learning Analytics are Learning Management Systems (LMS).These log files are limited though to interactions within the LMS and cannot take into account interactions of students in other applications and software in a digital learning environment. In this paper, we present an approach for generating log files based on mobile screen recordings as a data source for Learning Analytics. Logging mobile application usage is limited to rather general system events unless you have access to the source code of the operating system or applications.To address this we generate log files from mobile screen recordings by applying computer vision and machine learning methods to detect individually defined events. In closing, we discuss how these log files can be used as a data source for Learning Analytics and relevant ethical concerns.}, language = {en} } @article{Gerhards2025, author = {Gerhards, Claudia}, title = {Social Media Influencers as "Dirty Workers": An Explorative Study on How They Use Strategies to Reduce the Moral Taint}, series = {Social Media + Society}, volume = {11}, journal = {Social Media + Society}, number = {2}, publisher = {SAGE Publications}, issn = {2056-3051}, doi = {10.1177/20563051251348917}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-54189}, pages = {17}, year = {2025}, abstract = {Since social media influencers have become popular and monetize their content with the help of advertising deals, they have been associated with morally questionable, deceptive behavior. The list of misconduct is long. It includes, for example, not disclosing sponsored content, withholding negative experiences with promoted products, buying fake followers, and promoting false ideals of beauty. Building on the concept of "dirty work" as a theoretical framework, this article asks which strategies influencers use to soften this moral taint. Qualitative interviews with influencers living in Germany show that they are aware of their negative image in public and use various stigma management strategies. This article offers a perspective that has not yet played a role in the ethics debate about influencers. It asks how influencers, who are often associated with morally questionable practices, immunize themselves against this negative image and find a positive work identity.}, language = {en} } @incollection{Virchow2023, author = {Virchow, Fabian}, title = {„Wir hatten dann wirklich die Nase voll." Proteste gegen die rassistische Gewalt im Anschluss an die Morde in Solingen}, series = {Solingen, 30 Jahre nach dem Brandanschlag: Rassismus, extrem rechte Gewalt und die Narben einer vernachl{\"a}ssigten Aufarbeitung}, volume = {Edition Politik, Band 142}, booktitle = {Solingen, 30 Jahre nach dem Brandanschlag: Rassismus, extrem rechte Gewalt und die Narben einer vernachl{\"a}ssigten Aufarbeitung}, editor = {Demirtas, Birg{\"u}l and Schmit, Adelheid and G{\"u}r-Seker, Derya and Kahveci, {\c{C}}agri}, publisher = {Transcript}, address = {Bielefeld}, isbn = {978-3-8376-6497-3}, pages = {235 -- 244}, year = {2023}, language = {de} } @article{Hoerner2012, author = {H{\"o}rner, Fernand}, title = {„Was liegt daran wer spricht": Genderinszenierung durch Vielstimmigkeit im Musikvideo „Kiss" von Prince}, series = {Freiburger Zeitschrift f{\"u}r Geschlechterstudien}, volume = {18}, journal = {Freiburger Zeitschrift f{\"u}r Geschlechterstudien}, number = {1}, publisher = {Barabara Budrich}, organization = {Barabara Budrich}, issn = {2196-4459}, doi = {10.3224/fzg.v18i1.06}, pages = {53 -- 71}, year = {2012}, abstract = {Am Musikvideo „Kiss" von Prince and the Revolution (1986) werden exemplarisch verschiedene Verfahren beleuchtet, wie Gender durch „Stimme" im konkreten und abstrakten Sinn auf ambivalente Weise inszeniert wird. Michael Bachtins Metapher der fremden Stimme f{\"u}r das intertexuelle Verweisgeflecht von Sprache im Allgemeinen und Literatur im Besonderen wird hier sowohl im {\"u}bertragenen als auch im w{\"o}rtlichen Sinne verwendet und auf audiovisuelle Musikformate {\"u}bertragen. Das Spiel mit Gender entsteht durch eine komplexe Verwebung von intertextuellen und intermedialen Verweisen auf andere Liedtexte, Filme, Gesangstraditionen, Subkulturen etc. Dabei wird vestiment{\"a}res Cross-Dressing mit gesanglichem Cross-Dressing kombiniert.}, language = {de} } @article{NovelliKaminskiRolletteretal.2018, author = {Novelli, Anna and Kaminski, Martin and Rolletter, Michael and Acir, Ismail-Hakki and Bohn, Birger and Dorn, Hans-Peter and Li, Xin and Lutz, Anna and Nehr, Sascha and Rohrer, Franz and Tillmann, Ralf and Wegener, Robert and Holland, Frank and Hofzumahaus, Andreas and Kiendler-Scharr, Astrid and Wahner, Andreas and Fuchs, Hendrik}, title = {Evaluation of OH and HO2 concentrations and their budgets during photooxidation of 2-methyl-3-butene-2-ol (MBO) in the atmospheric simulation chamber SAPHIR}, series = {Atmospheric Chemistry and Physics}, volume = {18}, journal = {Atmospheric Chemistry and Physics}, number = {15}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-18-11409-2018}, pages = {11409 -- 11422}, year = {2018}, abstract = {Several previous field studies have reported unexpectedly large concentrations of hydroxyl and hydroperoxyl radicals (OH and HO2, respectively) in forested environments that could not be explained by the traditional oxidation mechanisms that largely underestimated the observations. These environments were characterized by large concentrations of biogenic volatile organic compounds (BVOC) and low nitrogen oxide concentration. In isoprene-dominated environments, models developed to simulate atmospheric photochemistry generally underestimated the observed OH radical concentrations. In contrast, HO2 radical concentration showed large discrepancies with model simulations mainly in non-isoprene-dominated forested environments. An abundant BVOC emitted by lodgepole and ponderosa pines is 2-methyl-3-butene-2-ol (MBO), observed in large concentrations for studies where the HO2 concentration was poorly described by model simulations. In this work, the photooxidation of MBO by OH was investigated for NO concentrations lower than 200 pptv in the atmospheric simulation chamber SAPHIR at Forschungszentrum J{\"u}lich. Measurements of OH and HO2 radicals, OH reactivity (kOH), MBO, OH precursors, and organic products (acetone and formaldehyde) were used to test our current understanding of the OH-oxidation mechanisms for MBO by comparing measurements with model calculations. All the measured trace gases agreed well with the model results (within 15 \%) indicating a well understood mechanism for the MBO oxidation by OH. Therefore, the oxidation of MBO cannot contribute to reconciling the unexplained high OH and HO2 radical concentrations found in previous field studies.}, language = {en} } @article{RolletterKaminskiAciretal.2019, author = {Rolletter, Michael and Kaminski, Martin and Acir, Ismail-Hakki and Bohn, Birger and Dorn, Hans-Peter and Li, Xin and Lutz, Anna and Nehr, Sascha and Rohrer, Franz and Tillmann, Ralf and Wegener, Robert and Hofzumahaus, Andreas and Kiendler-Scharr, Astrid and Wahner, Andreas and Fuchs, Hendrik}, title = {Investigation of the α-pinene photooxidation by OH in the atmospheric simulation chamber SAPHIR}, series = {Atmospheric Chemistry and Physics}, volume = {19}, journal = {Atmospheric Chemistry and Physics}, number = {18}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-19-11635-2019}, pages = {11635 -- 11649}, year = {2019}, abstract = {Abstract. The photooxidation of the most abundant monoterpene, α-pinene, by the hydroxyl radical (OH) was investigated at atmospheric concentrations in the atmospheric simulation chamber SAPHIR. Concentrations of nitric oxide (NO) were below 120 pptv. Yields of organic oxidation products are determined from measured time series giving values of 0.11±0.05, 0.19±0.06, and 0.05±0.03 for formaldehyde, acetone, and pinonaldehyde, respectively. The pinonaldehyde yield is at the low side of yields measured in previous laboratory studies, ranging from 0.06 to 0.87. These studies were mostly performed at reactant concentrations much higher than observed in the atmosphere. Time series of measured radical and trace-gas concentrations are compared to results from model calculations applying the Master Chemical Mechanism (MCM) 3.3.1. The model predicts pinonaldehyde mixing ratios that are at least a factor of 4 higher than measured values. At the same time, modeled hydroxyl and hydroperoxy (HO2) radical concentrations are approximately 25 \% lower than measured values. Vereecken et al. (2007) suggested a shift of the initial organic peroxy radical (RO2) distribution towards RO2 species that do not yield pinonaldehyde but produce other organic products. Implementing these modifications reduces the model-measurement gap of pinonaldehyde by 20 \% and also improves the agreement in modeled and measured radical concentrations by 10 \%. However, the chemical oxidation mechanism needs further adjustment to explain observed radical and pinonaldehyde concentrations. This could be achieved by adjusting the initial RO2 distribution, but could also be done by implementing alternative reaction channels of RO2 species that currently lead to the formation of pinonaldehyde in the model.}, language = {en} } @article{KaminskiFuchsAciretal.2017, author = {Kaminski, Martin and Fuchs, Hendrik and Acir, Ismail-Hakki and Bohn, Birger and Brauers, Theo and Dorn, Hans-Peter and H{\"a}seler, Rolf and Hofzumahaus, Andreas and Li, Xin and Lutz, Anna and Nehr, Sascha and Rohrer, Franz and Tillmann, Ralf and Vereecken, Luc and Wegener, Robert and Wahner, Andreas}, title = {Investigation of the β-pinene photooxidation by OH in the atmosphere simulation chamber SAPHIR}, series = {Atmospheric Chemistry and Physics}, volume = {17}, journal = {Atmospheric Chemistry and Physics}, number = {11}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-17-6631-2017}, pages = {6631 -- 6650}, year = {2017}, abstract = {Abstract. Besides isoprene, monoterpenes are the non-methane volatile organic compounds (VOCs) with the highest global emission rates. Due to their high reactivity towards OH, monoterpenes can dominate the radical chemistry of the atmosphere in forested areas. In the present study the photochemical degradation mechanism of β-pinene was investigated in the J{\"u}lich atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber). One focus of this study is on the OH budget in the degradation process. Therefore, the SAPHIR chamber was equipped with instrumentation to measure radicals (OH, HO2, RO2), the total OH reactivity, important OH precursors (O3, HONO, HCHO), the parent VOC β-pinene, its main oxidation products, acetone and nopinone and photolysis frequencies. All experiments were carried out under low-NO conditions ( ≤  300 ppt) and at atmospheric β-pinene concentrations ( ≤  5 ppb) with and without addition of ozone. For the investigation of the OH budget, the OH production and destruction rates were calculated from measured quantities. Within the limits of accuracy of the instruments, the OH budget was balanced in all β-pinene oxidation experiments. However, even though the OH budget was closed, simulation results from the Master Chemical Mechanism (MCM) 3.2 showed that the OH production and destruction rates were underestimated by the model. The measured OH and HO2 concentrations were underestimated by up to a factor of 2, whereas the total OH reactivity was slightly overestimated because the model predicted a nopinone mixing ratio which was 3 times higher than measured. A new, theory-derived, first-generation product distribution by Vereecken and Peeters (2012) was able to reproduce the measured nopinone time series and the total OH reactivity. Nevertheless, the measured OH and HO2 concentrations remained underestimated by the numerical simulations. These observations together with the fact that the measured OH budget was closed suggest the existence of unaccounted sources of HO2. Although the mechanism of additional HO2 formation could not be resolved, our model studies suggest that an activated alkoxy radical intermediate proposed in the model of Vereecken and Peeters (2012) generates HO2 in a new pathway, whose importance has been underestimated so far. The proposed reaction path involves unimolecular rearrangement and decomposition reactions and photolysis of dicarbonyl products, yielding additional HO2 and CO. Further experiments and quantum chemical calculations have to be made to completely unravel the pathway of HO2 formation.}, language = {en} } @article{FuchsAcirBohnetal.2014, author = {Fuchs, H. and Acir, Ismail-Hakki and Bohn, Birger and Brauers, Theo and Dorn, Hans-Peter and H{\"a}seler, R. and Hofzumahaus, A. and Holland, F. and Kaminski, M. and Li, X. and Lu, K. and Lutz, A. and Nehr, Sascha and Rohrer, F. and Tillmann, R. and Wegener, R. and Wahner, A.}, title = {OH regeneration from methacrolein oxidation investigated in the atmosphere simulation chamber SAPHIR}, series = {Atmospheric Chemistry and Physics}, volume = {14}, journal = {Atmospheric Chemistry and Physics}, number = {15}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-14-7895-2014}, pages = {7895 -- 7908}, year = {2014}, abstract = {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.}, language = {en} } @article{NehrBohnDornetal.2014, author = {Nehr, Sascha and Bohn, Birger and Dorn, Hans-Peter and Fuchs, H. and H{\"a}seler, R. and Hofzumahaus, A. and Li, X. and Rohrer, F. and Tillmann, R. and Wahner, A.}, title = {Atmospheric photochemistry of aromatic hydrocarbons: OH budgets during SAPHIR chamber experiments}, series = {Atmospheric Chemistry and Physics}, volume = {14}, journal = {Atmospheric Chemistry and Physics}, number = {13}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-14-6941-2014}, pages = {6941 -- 6952}, year = {2014}, abstract = {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.}, language = {en} } @article{EmanuelssonHallquistKristensenetal.2013, author = {Emanuelsson, E. U. and Hallquist, M. and Kristensen, K. and Glasius, M. and Bohn, Birger and Fuchs, H. and Kammer, B. and Kiendler-Scharr, A. and Nehr, Sascha and Rubach, F. and Tillmann, R. and Wahner, A. and Wu, H.-C. and Mentel, Th. F.}, title = {Formation of anthropogenic secondary organic aerosol (SOA) and its influence on biogenic SOA properties}, series = {Atmospheric Chemistry and Physics}, volume = {13}, journal = {Atmospheric Chemistry and Physics}, number = {5}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-13-2837-2013}, pages = {2837 -- 2855}, year = {2013}, abstract = {Abstract. Secondary organic aerosol (SOA) formation from mixed anthropogenic and biogenic precursors has been studied exposing reaction mixtures to natural sunlight in the SAPHIR chamber in J{\"u}lich, Germany. In this study aromatic compounds served as examples of anthropogenic volatile organic compound (VOC) and a mixture of α-pinene and limonene as an example for biogenic VOC. Several experiments with exclusively aromatic precursors were performed to establish a relationship between yield and organic aerosol mass loading for the atmospheric relevant range of aerosol loads of 0.01 to 10 μg m-3. The yields (0.5 to 9\%) were comparable to previous data and further used for the detailed evaluation of the mixed biogenic and anthropogenic experiments. For the mixed experiments a number of different oxidation schemes were addressed. The reactivity, the sequence of addition, and the amount of the precursors influenced the SOA properties. Monoterpene oxidation products, including carboxylic acids and dimer esters were identified in the aged aerosol at levels comparable to ambient air. OH radicals were measured by Laser Induced Fluorescence, which allowed for establishing relations of aerosol properties and composition to the experimental OH dose. Furthermore, the OH measurements in combination with the derived yields for aromatic SOA enabled application of a simplified model to calculate the chemical turnover of the aromatic precursor and corresponding anthropogenic contribution to the mixed aerosol. The estimated anthropogenic contributions were ranging from small (\&amp;approx;8\%) up to significant fraction (50\%) providing a suitable range to study the effect of aerosol composition on the aerosol volatility (volume fraction remaining (VFR) at 343 K: 0.86-0.94). The aromatic aerosol had higher oxygen to carbon ratio O/C and was less volatile than the biogenic fraction. However, in order to produce significant amount of aromatic SOA the reaction mixtures needed a higher OH dose that also increased O/C and provided a less volatile aerosol. The SOA yields, O/C, and f44 (the mass fraction of CO2+ ions in the mass spectra which can be considered as a measure of carboxylic groups) in the mixed photo-chemical experiments could be described as linear combinations of the corresponding properties of the pure systems. For VFR there was in addition an enhancement effect, making the mixed aerosol significantly less volatile than what could be predicted from the pure systems. A strong positive correlation was found between changes in volatility and O/C with the exception during dark hours where the SOA volatility decreased while O/C did not change significantly. Thus, this change in volatility under dark conditions as well as the anthropogenic enhancement is due to chemical or morphological changes not affecting O/C.}, language = {en} } @article{LuRohrerHollandetal.2012, author = {Lu, K. D. and Rohrer, F. and Holland, F. and Fuchs, H. and Bohn, Birger and Brauers, Theo and Chang, C. C. and H{\"a}seler, R. and Hu, M. and Kita, K. and Kondo, Y. and Li, X. and Lou, S. R. and Nehr, Sascha and Shao, M. and Zeng, L. M. and Wahner, A. and Zhang, Y. H. and Hofzumahaus, A.}, title = {Observation and modelling of OH and HO2 concentrations in the Pearl River Delta 2006: a missing OH source in a VOC rich atmosphere}, series = {Atmospheric Chemistry and Physics}, volume = {12}, journal = {Atmospheric Chemistry and Physics}, number = {3}, publisher = {Copernicus}, issn = {1680-7324}, doi = {10.5194/acp-12-1541-2012}, pages = {1541 -- 1569}, year = {2012}, abstract = {Abstract. Ambient OH and HO2 concentrations were measured by laser induced fluorescence (LIF) during the PRIDE-PRD2006 (Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta, 2006) campaign at a rural site downwind of the megacity of Guangzhou in Southern China. The observed OH concentrations reached daily peak values of (15-26) × 106 cm-3 which are among the highest values so far reported for urban and suburban areas. The observed OH shows a consistent high correlation with j(O1D) over a broad range of NOx conditions. The correlation cannot be reproduced by model simulations, indicating that OH stabilizing processes are missing in current models. The observed OH exhibited a weak dependence on NOx in contrast to model predictions. While modelled and measured OH agree well at NO mixing ratios above 1 ppb, a continuously increasing underprediction of the observed OH is found towards lower NO concentrations, reaching a factor of 8 at 0.02 ppb NO. A dependence of the modelled-to-measured OH ratio on isoprene cannot be concluded from the PRD data. However, the magnitude of the ratio fits into the isoprene dependent trend that was reported from other campaigns in forested regions. Hofzumahaus et al. (2009) proposed an unknown OH recycling process without NO, in order to explain the high OH levels at PRD in the presence of high VOC reactivity and low NO. Taking a recently discovered interference in the LIF measurement of HO2 into account, the need for an additional HO2 → OH recycling process persists, but the required source strength may be up to 20\% larger than previously determined. Recently postulated isoprene mechanisms by Lelieveld et al. (2008) and Peeters and M{\"u}ller (2010) lead to significant enhancements of OH expected for PRD, but an underprediction of the observed OH by a factor of two remains at low NO (0.1-0.2 ppb). If the photolysis of hydroperoxy aldehydes from isoprene is as efficient as proposed by Peeters and M{\"u}ller (2010), the corresponding OH formation at PRD would be more important than the primary OH production from ozone and HONO. While the new isoprene mechanisms need to be confirmed by laboratory experiments, there is probably need for other, so far unidentified chemical processes to explain entirely the high OH levels observed in Southern China.}, language = {en} } @article{FuchsDornBachneretal.2012, author = {Fuchs, H. and Dorn, Hans-Peter and Bachner, M. and Bohn, Birger and Brauers, Theo and Gomm, S. and Hofzumahaus, A. and Holland, F. and Nehr, Sascha and Rohrer, F. and Tillmann, R. and Wahner, A.}, title = {Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration}, series = {Atmospheric Measurement Techniques}, volume = {5}, journal = {Atmospheric Measurement Techniques}, number = {7}, publisher = {Copernicus}, issn = {1867-8548}, doi = {10.5194/amt-5-1611-2012}, pages = {1611 -- 1626}, year = {2012}, abstract = {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 J{\"u}lich, 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.}, language = {en} } @article{FuchsBohnHofzumahausetal.2011, author = {Fuchs, H. and Bohn, Birger and Hofzumahaus, A. and Holland, F. and Lu, K. D. and Nehr, Sascha and Rohrer, F. and Wahner, A.}, title = {Detection of HO2 by laser-induced fluorescence: calibration and interferences from RO2 radicals}, series = {Atmospheric Measurement Techniques}, volume = {4}, journal = {Atmospheric Measurement Techniques}, number = {6}, publisher = {Copernicus}, issn = {1867-8548}, doi = {10.5194/amt-4-1209-2011}, pages = {1209 -- 1225}, year = {2011}, abstract = {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.}, language = {en} } @inproceedings{HenningsMusall2024, author = {Hennings, Detlef and Musall, Eike}, title = {Raumakustische Modell-Messungen in der Architekten-Ausbildung [Vortrag]}, series = {Fortschritte der Akustik - DAGA 2024, 18. - 21. M{\"a}rz 2024, Hannover}, booktitle = {Fortschritte der Akustik - DAGA 2024, 18. - 21. M{\"a}rz 2024, Hannover}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, address = {Berlin}, isbn = {978-3-939296-22-5}, pages = {822 -- 825}, year = {2024}, abstract = {Raumakustische Messungen in Modellen sind in der Planung von Konzerts{\"a}len und {\"a}hnlichen R{\"a}umen seit Jahrzehnten g{\"a}ngige Praxis. Der große Vorzug gegen{\"u}ber mathematischer Modellierung - das Modell beruht auf denselben physikalischen Zusammenh{\"a}ngen wie das Vorbild - kann auch in der Akustik-Lehre an Hochschulen genutzt werden. In einem Lehrprojekt zu raumakustischen Modell-Messungen im Fachbereich Architektur der Hochschule D{\"u}sseldorf wird ein Modellraum gebaut und vermessen. Dabei wird die neu entwickelte Software 'AcouScale' mit integrierten Algorithmen f{\"u}r die Maßstabs-Transformation und f{\"u}r die Korrektur der Meßabweichungen durch Schallabsorption der Luft eingesetzt. Im Beitrag wird von diesem Lehrprojekt berichtet und die Software 'AcouScale' vorgestellt. Die Software und ein zugeh{\"o}riges Anwender-Handbuch sind von einer Projekt-Seite herunterladbar und stehen f{\"u}r Lehre und Forschung kostenfrei zur Verf{\"u}gung.}, language = {de} } @article{JakabVazquezBartheletal.2025, author = {Jakab, Daniel and V{\´a}zquez, Joel Herrera and Barthel, Julian and Honsbrok, Jan and Deegan, Brian and Mohandas, Reenu and Brophy, Tim and Scanlan, Anthony and Ward, Enda and Collins, Fiachra and Eising, Ciar{\´a}n and Braun, Alexander}, title = {SOLAS 1.1: Automotive Optical Simulation in Computer Vision (Early Access)}, series = {IEEE Open Journal of Vehicular Technology}, journal = {IEEE Open Journal of Vehicular Technology}, publisher = {Institute of Electrical and Electronics Engineers}, issn = {2644-1330}, doi = {10.1109/OJVT.2025.3640419}, pages = {1 -- 16}, year = {2025}, language = {en} } @article{NiemannBassonFusseneckeretal.2018, author = {Niemann, J{\"o}rg and Basson, A. and Fussenecker, Claudia and Kruger, K. and Schl{\"o}sser, M. and Turek, S. and Amarnath, H. Umadevi}, title = {Implementation of Eye-Tracking Technology in Holonic Manufacturing Systems}, series = {Procedia - Social and Behavioral Sciences}, volume = {238}, journal = {Procedia - Social and Behavioral Sciences}, edition = {SIM 2017: 14th International Symposium in Management, Challenges and Innovation in Management and Entrepreneurship}}, publisher = {Elsevier}, doi = {10.1016/j.sbspro.2018.03.005}, pages = {37 -- 45}, year = {2018}, language = {en} } @article{KacsoVidreanNiemannBaidocetal.2018, author = {Kacso-Vidrean, Lorand and Niemann, J{\"o}rg and Baidoc, Raluca and Pisla, Adrian}, title = {Change Management Aspects in Solar Energy Implementation}, series = {Procedia - Social and Behavioral Sciences}, volume = {238}, journal = {Procedia - Social and Behavioral Sciences}, edition = {SIM 2017 / 14th International Symposium in Management}, publisher = {Elsevier}, doi = {10.1016/j.sbspro.2018.04.021}, pages = {432 -- 441}, year = {2018}, subject = {FliX}, language = {en} } @incollection{MichaelisHerder2025, author = {Michaelis, Maja and Herder, Jens}, title = {Augmented Reality for Lighting Adjustment in a Virtual Studio}, series = {Augmented Reality - Situated Spatial Synergy [Working Title]}, booktitle = {Augmented Reality - Situated Spatial Synergy [Working Title]}, editor = {Cohen, Michael}, publisher = {IntechOpen}, address = {London}, doi = {10.5772/intechopen.1012424}, publisher = {Hochschule D{\"u}sseldorf}, year = {2025}, abstract = {An interactive virtual studio is used for live broadcasts with live interaction in front of the recording system. Advances in Augmented Reality (AR) using video see-through Head-Mounted Displays (HMDs) also make it possible to improve the production process itself. Lighting can be improved and adjusted using AR while seeing live effects. An Augmented Reality Lighting Adjustment System (ARLAS) for a virtual studio has been developed and evaluated. The traditional process for controlling lighting in a virtual studio is complicated and time-consuming. It often requires several people to control many different components at different locations. Using AR, this process is simplified by integrating relevant programs and video streams into a single application on an HMD, allowing direct control at lighting locations. Changes to settings are immediately visible on the real fixtures. Real lights can be replicated virtually to maintain consistent lighting conditions in virtual scenes, ensuring that virtual objects are lit as they would be in a real studio. The prototype demonstrated the benefits of AR for complex virtual studio setups and was evaluated by 18 participants.}, subject = {Erweiterte Realit{\"a}t (Informatik)}, language = {en} } @incollection{BleckHoeppner2025, author = {Bleck, Christian and H{\"o}ppner, Grit}, title = {Altenhilfe}, series = {Handw{\"o}rterbuch Sozialraumorientierte Soziale Arbeit}, booktitle = {Handw{\"o}rterbuch Sozialraumorientierte Soziale Arbeit}, editor = {Noack, Michael and Nuss, Felix Manuel}, publisher = {Beltz Juventa}, address = {Weinheim}, isbn = {978-3-7799-7659-2}, doi = {10.3262/978-3-7799-7659-2}, publisher = {Hochschule D{\"u}sseldorf}, pages = {272 -- 274}, year = {2025}, subject = {Sozialraum}, language = {de} }