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Now showing items 1031-1040 of 1132
Aufsatz
Resistance of poly(lactic acid)/starch composites to weathering effects
(2023-10-06)
In order to produce a completely bio-based and cost-effective filled polymer, PLA and native potato starch as a filler were compounded by twin screw extrusion. Subsequently injection molded test specimens were manufactured and subjected to artificial weathering as well as different storages (high temperature, high humidity, freeze, water) for 504 h with a view to long-term resistance. Depending on the starch content a significant reduction of up to 100% in tensile strength can be seen, as the starch accelerates or ...
Aufsatz
Model Specification Searches in Structural Equation Modeling Using Bee Swarm Optimization
(2023-03-29)
Metaheuristics are optimization algorithms that efficiently solve a variety of complex combinatorial problems. In psychological research, metaheuristics have been applied in short-scale construction and model specification search. In the present study, we propose a bee swarm optimization (BSO) algorithm to explore the structure underlying a psychological measurement instrument. The algorithm assigns items to an unknown number of nested factors in a confirmatory bifactor model, while simultaneously selecting items for ...
Aufsatz
Funktionalisierung faserverstärkter Hochleistungsbetone mittels Formgedächtnislegierungen
(2023-12-06)
Faserverstärkte (Ultra-)Hochleistungsbetone ((U)HPC) werden bereits seit den 1970er Jahren in großen Mengen für die Herstellung von Betonfertigteilen verwendet. Fasern werden eingesetzt, um die Zugfestigkeit zu erhöhen und sprödes Versagen in duktiles Nachbruchverhalten umzuwandeln. Funktionale Formgedächtnislegierungen (FGL) als Bewehrung haben das Potenzial, in Form von Vorspannelementen im erhärteten Beton zu wirken und die Frischbetoneigenschaften zu verbessern.
FGL haben die Eigenschaft, sich an eine eingeprägte ...
Aufsatz
Faserbewehrter UHPC auf Basis von alkalisch aktivierten Bindemittel
(2023-12-06)
Die mechanische Leistungsfähigkeit von faserverstärktem Ultrahochleistungsbeton auf der Grundlage alkalisch aktivierter Schlacke wurde untersucht, wobei der Schwerpunkt auf der Verwendung von Stahlfasern lag. Die Biegezugfestigkeit ist im Vergleich zu UHPC auf der Basis Portlandzement als Bindemittel erhöht. Die Korrelation der Biegezugfestigkeitsprüfung mit Faserauszugsversuchen ergab eine Verbesserung des Verbundverhaltens in der Grenzflächen-Übergangszone des AAM-UHPC im Vergleich zum OPC-UHPC. Bei Vergleichen von ...
Aufsatz
Spatially resolved in situ analyses of the adsorption behavior of different admixtures on binders
(2023-12-06)
Admixtures play a key role in improving the performance of the cement paste matrix. A more efficient matrix can allow a reduction the binder content while maintaining the same properties. There is currently a lack of knowledge about the spatial distribution of admixtures in situ on binder surfaces which would facilitate the use of admixtures in general in inorganic binder systems. Imaging techniques such as confocal laser scanning microscopy (CLSM) and fluorescence microscopy can be used to study the spatiotemporal ...
Aufsatz
Fracture behavior of ultra-high performance lightweight concrete: In situ investigations using μ-CT
(2023-12-06)
In various research projects at the University of Kassel, the concept of lightweight concrete has been combined with that of ultra-high performance concrete (UHPC). Due to the high performance of the UHPC matrix, lightweight concretes (UHPLC) with strengths of 60-130 MPa and bulk density of 1.5-1.9 kg/m³ were developed. This material can be used in many applications because of its low thermal conductivity, low weight and thus easy to transport, recyclable and can be prefabricated. Thus, it meets today's multifunctional ...
Aufsatz
Medicalizing disabled people’s emotions - Symptom of a dis/ableist society
(2023-12-11)
The theoretical - conceptual article at hand explores how emotional discourses shape social relations by specifically focusing on the medicalization of disabled - and chronically ill - people's emotions. Medicalization is a concept from medical sociology that describes medicine's expansion into non-medical life areas, for instance into the realm of emotions, sometimes in order to challenge this expansion. The emotions of disabled people are often presented as a medicalized problem, rather than recognizing their ...
Aufsatz
The effects of social norms and observability on food choice
(2024-05-04)
People often adapt their behavior to the behavior of other people. We test with the help of an experiment whether this also applies to the choice of food and whether the sensitivity regarding others’ behavior increases when the food choice is observable. Participants in the experiment are first-year students who are confronted with different statements about the diets of students already enrolled and studying at the university. Participants then choose between vouchers for vegan, vegetarian, or meat-based foods, with ...
Aufsatz
The Translatio imperii and the Spatial Construction of History in the Twelfth Century
(2024-03-13)
Based on the theories of Otto of Freising and Hugh of Saint Victor, scholars widely accept that medieval authors conceived of history as a spatial progression of empires from Babylon in the east to Rome in the west. This article reevaluates that assumption, arguing that influential German scholars of the 1930s to 1960s inflated the perceived typicality of Otto’s writing. We see first that this has obscured the biblical exegetical basis of Hugh’s own theory. Surveying contemporary material from hagiographies of Thomas ...
Aufsatz
Leading in times of crisis and remote work: perceived consideration leadership behavior and its effect on follower work engagement
(2024-03-20)
Based on the job-demands resources theory, we examine whether leadership behavior affects followers' work engagement in the context of remote work during times of crisis, and how this effect can be explained. We focus on consideration leadership and its impact on followers' engagement under conditions of enforced remote work during the COVID-19 pandemic. Therein, we examine the role of optimism as a potential mediator. To better understand how the impact of consideration leadership behavior unfolds during crises, we ...