@article{RabczukZhuangOterkus, author = {Rabczuk, Timon and Zhuang, Xiaoying and Oterkus, Erkan}, title = {Editorial: Computational modeling based on nonlocal theory}, series = {Engineering with Computers}, volume = {2023}, journal = {Engineering with Computers}, number = {Volume 39, issue 3}, publisher = {Springer}, address = {London}, doi = {https://doi.org/10.1007/s00366-022-01775-7}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230517-63658}, pages = {1}, abstract = {Nonlocal theories concern the interaction of objects, which are separated in space. Classical examples are Coulomb's law or Newton's law of universal gravitation. They had signficiant impact in physics and engineering. One classical application in mechanics is the failure of quasi-brittle materials. While local models lead to an ill-posed boundary value problem and associated mesh dependent results, nonlocal models guarantee the well-posedness and are furthermore relatively easy to implement into commercial computational software.}, subject = {Computersimulation}, language = {en} } @article{WiegandOsburg, author = {Wiegand, Torben and Osburg, Andrea}, title = {Synthesis, Curing and Thermal Behavior of Amine Hardeners from Potentially Renewable Sources}, series = {Polymers}, volume = {2023}, journal = {Polymers}, number = {volume 15, issue 4, article 990}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/polym15040990}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230524-63745}, pages = {1 -- 12}, abstract = {Research into bio-based epoxy resins has intensified in recent decades. Here, it is of great importance to use raw materials whose use does not compete with food production. In addition, the performance of the newly developed materials should be comparable to that of conventional products. Possible starting materials are lignin degradation products, such as vanillin and syringaldehyde, for which new synthesis routes to the desired products must be found and their properties determined. In this article, the first synthesis of two amine hardeners, starting with vanillin and syringaldehyde, using the Smiles rearrangement reaction is reported. The amine hardeners were mixed with bisphenol A diglycidyl ether, and the curing was compared to isophorone diamine, 4-4′-diaminodiphenyl sulfone, and 4-Aminonbenzylamine by means of differential scanning calorimetry. It was found that the two amines prepared are cold-curing. As TG-MS studies showed, the thermal stability of at least one of the polymers prepared with the potentially bio-based amines is comparable to that of the polymer prepared with isophorone diamine, and similar degradation products are formed during pyrolysis.}, subject = {Epoxide}, language = {en} } @article{PartschefeldTutalHalmansederetal., author = {Partschefeld, Stephan and Tutal, Adrian and Halmanseder, Thomas and Schneider, Jens and Osburg, Andrea}, title = {Investigations on Stability of Polycarboxylate Superplasticizers in Alkaline Activators for Geopolymer Binders}, series = {Materials}, volume = {2023}, journal = {Materials}, number = {Volume 16, issue 15, article 5369}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/ma16155369}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20231026-64809}, pages = {1 -- 14}, abstract = {Calcined clays are interesting starting materials to be used as SCMs (supplementary cementitious materials) in cements or to be converted to geopolymers by activation with a high alkaline activator. The adjustment of the properties in the fresh state, especially regarding the consistency of these binders, is almost exclusively achieved by the addition of water, since commercially available superplasticizers seem to be ineffective in low-calcium geopolymer systems. The aim of this study was a systematic investigation of various PCE (polycarboxylate ester/ether) superplasticizers (methacrylate ester PCE: MPEG, isoprenol ether PCE: IPEG, methallyl ether PCE: HPEG) with respect to their stability in different alkaline activators (NaOH, KOH, sodium and potassium silicate solutions). The effectiveness of superplasticizers (SPs) in low-calcium geopolymer binders was verified by rheological tests. Size exclusion chromatography was used to investigate if structural degradation of the superplasticizers occurs. The investigated PCE superplasticizers showed a thickening effect in the low-calcium geopolymer system. Depending on the alkalinity of the activator solution, a degradation process was detected for all the PCEs investigated. The side chains of the PCEs are cleaved off the backbone by basic ester and ether hydrolysis. The highest degree of degradation was found in sodium and potassium silicate solutions. In alkaline hydroxide solutions, the degradation process increases with increasing alkalinity.}, subject = {Geopolymere}, language = {en} } @article{AlsaadSchaelteSchneeweissetal., author = {Alsaad, Hayder and Sch{\"a}lte, Gereon and Schneeweiß, Mario and Becher, Lia and Pollack, Moritz and Gena, Amayu Wakoya and Schweiker, Marcel and Hartmann, Maria and Voelker, Conrad and Rossaint, Rolf and Irrgang, Matthias}, title = {The Spread of Exhaled Air and Aerosols during Physical Exercise}, series = {Journal of Clinical Medicine}, volume = {2023}, journal = {Journal of Clinical Medicine}, number = {Volume 12, issue 4, article 1300}, publisher = {Basel}, address = {MDPI}, doi = {10.3390/jcm12041300}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230208-49262}, pages = {20}, abstract = {Physical exercise demonstrates a special case of aerosol emission due to its associated elevated breathing rate. This can lead to a faster spread of airborne viruses and respiratory diseases. Therefore, this study investigates cross-infection risk during training. Twelve human subjects exercised on a cycle ergometer under three mask scenarios: no mask, surgical mask, and FFP2 mask. The emitted aerosols were measured in a grey room with a measurement setup equipped with an optical particle sensor. The spread of expired air was qualitatively and quantitatively assessed using schlieren imaging. Moreover, user satisfaction surveys were conducted to evaluate the comfort of wearing face masks during training. The results indicated that both surgical and FFP2 masks significantly reduced particles emission with a reduction efficiency of 87.1\% and 91.3\% of all particle sizes, respectively. However, compared to surgical masks, FFP2 masks provided a nearly tenfold greater reduction of the particle size range with long residence time in the air (0.3-0.5 μm). Furthermore, the investigated masks reduced exhalation spreading distances to less than 0.15 m and 0.1 m in the case of the surgical mask and FFP2 mask, respectively. User satisfaction solely differed with respect to perceived dyspnea between no mask and FFP2 mask conditions.}, subject = {Sport}, language = {en} } @article{BrokowLogaKrueger, author = {Brokow-Loga, Anton and Kr{\"u}ger, Timmo}, title = {Potentials of Climate Emergency Declarations for degrowth transformations. The ambivalent stance of German municipalities in conflicts over a post-fossil future}, series = {Raumforschung und Raumordnung}, volume = {2023}, journal = {Raumforschung und Raumordnung}, number = {Vol. 81, No. 5}, publisher = {oekom Verlag}, address = {M{\"u}nchen}, doi = {10.14512/rur.1666}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20231204-64984}, pages = {523 -- 537}, abstract = {This paper addresses the scope for action by municipalities in a climate emergency and places it in the framework of ecomodern (urban) policy. We analyse the way in which two German 'climate emergency municipalities' translate conflicts of post-fossil transformation into concrete political and planning strategies. Although more than 2,200 authorities around the world have already declared a climate emergency, research on the impact of these resolutions on the political orientation of municipalities is very limited. Our research focus is on the (potentially agonistic) treatment of conflicts in planning. We argue that in times of a socio-ecological crisis, success in conflict resolution cannot refer to appeasement and depoliticisation. Instead, we propose a framework of five criteria, based on critical theory on ecomodern strategies, planning processes and degrowth. Thus, this practice-related and explorative paper connects empirical insights from the German cities of Constance and Berlin with an innovative normative framework. The findings tell a complex story of an, at least partial, admission of the failure of previous climate mitigation strategies, a lack of social institutions of limits, an instrumental relation to nature and a disregard for social injustices. The paper discusses how municipalities, in the context of ongoing tensions over the post-fossil transformation in Germany, on the one hand hold on to business-as-usual approaches, but on the other hand also set political impulses for change.}, subject = {Stadtentwicklung}, language = {de} } @article{Suhr, author = {Suhr, Maike}, title = {Diversit{\"a}t und (Anti-)Diskriminierung im Kontext journalistischer Neugr{\"u}ndungen: Eine Forschungsagenda}, series = {Global Media Journal German Edition}, volume = {2023}, journal = {Global Media Journal German Edition}, number = {Volume 13, No 1}, doi = {10.22032/dbt.57907}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20231027-64836}, pages = {1 -- 19}, abstract = {Obgleich redaktionelle Diversit{\"a}t regelm{\"a}ßig als eine der Kernherausforderungen f{\"u}r den Journalismus gehandelt wird, tun sich journalistische Organisationen immer noch schwer damit, gleichberechtigte Zugangs-und Entfaltungschancen f{\"u}r Frauen, People of Color, Menschen aus Einwandererfamilien oder auf anderen Ebenen diskriminierungsbetroffene Journalist*innen zu schaffen. Stattdessen zeigt die gender-und diversit{\"a}tsbezogene Redaktionsforschung, dass Redaktionen nach wie vor in ihren Strukturen, Praktiken und in ihrer Kultur gesellschaftliche Machtverh{\"a}ltnisse widerspiegeln und (re-)produzieren. Doch im Zuge des „Entrepreneurial Journalism" entstehen heute vielerorts neue Organisationen. Diese journalistischen Neugr{\"u}ndungen zeichnen sich unter anderem durch kleinere, offenere und flexiblere Organisationsstrukturen aus. Ihr ver{\"a}nderter organisationaler Charakter wurde jedoch bislang noch nicht tiefergehend im Hinblick auf seine Potenziale und m{\"o}glichen Risiken f{\"u}r Diversit{\"a}t und (Anti-)Diskriminierung untersucht. Der Beitrag hat somit zum Ziel, journalistische Neugr{\"u}ndungen als neuen Gegenstand auf der Agenda der organisations-und diskriminierungsbezogenen Journalismusforschung zu positionieren. Dazu werden ausgew{\"a}hlte Studien zum „Entrepreneurial Journalism" im Hinblick auf Diversit{\"a}t und (Anti-)Diskriminierung aufgearbeitet und bestehende Desiderata identifiziert. Auf dieser Grundlage wird schließlich eine programmatische Forschungsagenda entwickelt, um empirische Folgeforschung zum Thema anzustoßen.}, subject = {Journalismus}, language = {de} } @article{BapirAbrahamczykWichtmannetal., author = {Bapir, Baban and Abrahamczyk, Lars and Wichtmann, Torsten and Prada-Sarmiento, Luis Felipe}, title = {Soil-structure interaction: A state-of-the-art review of modeling techniques and studies on seismic response of building structures}, series = {Frontiers in Built Environment}, volume = {2023}, journal = {Frontiers in Built Environment}, number = {Volume 9}, editor = {Ozturk, Baki}, publisher = {Frontiers Media}, address = {Lausanne}, doi = {10.3389/fbuil.2023.1120351}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230206-49190}, pages = {1 -- 17}, abstract = {The present article aims to provide an overview of the consequences of dynamic soil-structure interaction (SSI) on building structures and the available modelling techniques to resolve SSI problems. The role of SSI has been traditionally considered beneficial to the response of structures. However, contemporary studies and evidence from past earthquakes showed detrimental effects of SSI in certain conditions. An overview of the related investigations and findings is presented and discussed in this article. Additionally, the main approaches to evaluate seismic soil-structure interaction problems with the commonly used modelling techniques and computational methods are highlighted. The strength, limitations, and application cases of each model are also discussed and compared. Moreover, the role of SSI in various design codes and global guidelines is summarized. Finally, the advancements and recent findings on the SSI effects on the seismic response of buildings with different structural systems and foundation types are presented. In addition, with the aim of helping new researchers to improve previous findings, the research gaps and future research tendencies in the SSI field are pointed out.}, subject = {Boden-Bauwerk-Wechselwirkung}, language = {en} } @article{WellbrockLobigsErbrichetal., author = {Wellbrock, Christian-Mathias and Lobigs, Frank and Erbrich, Lukas and Buschow, Christopher}, title = {Coopetition is King. {\"O}konomische Potentiale und medienpolitische Implikationen kooperativer Journalismusplattformen}, volume = {2023}, publisher = {Landesanstalt f{\"u}r Medien NRW}, address = {D{\"u}sseldorf}, doi = {10.25643/bauhaus-universitaet.4947}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230320-49473}, pages = {1 -- 48}, abstract = {Die vorliegende Studie geht der Fragestellung nach, wie sich eine anbieter{\"u}bergreifende, abonnementbasierte Plattform f{\"u}r den digitalen Journalismus, also eine Art Spotify im Journalismus, auf die Ums{\"a}tze der Anbieter journalistischer Inhalte und die Abonnements im Digitaljournalismus in Deutschland auswirken w{\"u}rde. Auf Basis drei sich erg{\"a}nzender Sch{\"a}tzmethoden f{\"u}r Zahlungsbereitschaft, die in zwei Repr{\"a}sentativbefragungen der deutschen Online-Bev{\"o}lkerung mit insgesamt 8.000 Teilnehmenden angewandt wurden, gelangt das Whitepaper zu den folgenden Schl{\"u}sselbefunden.}, subject = {Journalistik}, language = {de} } @article{LondongBarthSoebke, author = {Londong, J{\"o}rg and Barth, Marcus and S{\"o}bke, Heinrich}, title = {Reducing antimicrobial resistances by source separation of domestic wastewater}, series = {Frontiers in Environmental Health}, volume = {2023}, journal = {Frontiers in Environmental Health}, number = {Volume 2, article 1151898}, publisher = {Frontiers Media}, address = {Lausanne}, doi = {10.3389/fenvh.2023.1151898}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230403-49483}, pages = {1 -- 5}, abstract = {Antimicrobial resistances (AMR) are ranked among the top ten threats to public health and societal development worldwide. Toilet wastewater contained in domestic wastewater is a significant source of AMR entering the aquatic environment. The current commonly implemented combined sewer systems at times cause overflows during rain events, resulting in the discharge of untreated wastewater into the aquatic environment, thus promoting AMR. In this short research article, we describe an approach to transform combined sewer systems into source separation-modified combined sewer systems that separately treat toilet wastewater. We employ simulations for demonstrating that source separation-modified combined sewer systems reduce the emission of AMR- causing substances by up to 11.5 logarithm levels. Thus, source separation- modified combined sewer systems are amongst the most effective means of combating AMR. KEYWORDS}, subject = {Allgemeinheit}, language = {en} } @article{AnsariZachariasKoenke, author = {Ansari, Meisam and Zacharias, Christin and K{\"o}nke, Carsten}, title = {Metaconcrete: An Experimental Study on the Impact of the Core-Coating Inclusions on Mechanical Vibration}, series = {materials}, volume = {2023}, journal = {materials}, number = {Volume 16, Issue 5, article 1836}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/ma16051836}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230315-49370}, pages = {1 -- 18}, abstract = {Resonance vibration of structures is an unpleasant incident that can be conventionally avoided by using a Tuned Mass Damper (TMD). The scope of this paper contains the utilization of engineered inclusions in concrete as damping aggregates to suppress resonance vibration similar to a TMD. The inclusions are composed of a stainless-steel core with a spherical shape coated with silicone. This configuration has been the subject of several studies and it is best known as Metaconcrete. This paper presents the procedure of a free vibration test conducted with two small-scaled concrete beams. The beams exhibited a higher damping ratio after the core-coating element was secured to them. Subsequently, two meso-models of small-scaled beams were created: one representing conventional concrete and the other representing concrete with the core-coating inclusions. The frequency response curves of the models were obtained. The change in the response peak verified the ability of the inclusions to suppress the resonance vibration. This study concludes that the core-coating inclusions can be utilized in concrete as damping aggregates.}, subject = {Beton}, language = {en} }