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Now showing items 61-70 of 148
Aufsatz
Fluorescence microscopic investigation of PCE superplasticiser adsorption in calcined clay blended cement
(2024-03-31)
Global efforts to minimise carbon dioxide emissions are also leading to attempts to use calcined clays (CC) as a partial substitute for cement in concrete. While the hydration mechanism of such CC blended cements is now well understood, the range of effective admixtures like polycarboxylate ethers (PCE) is limited. There are PCE types that promise relatively high effectiveness, but the mechanisms of action are not yet sufficiently understood. For a detailed understanding of the adsorption of such PCEs, spatially ...
Aufsatz
Chitosan hydrogels enriched with bioactive phloroglucinol for controlled drug diffusion and potential wound healing
(2024-04)
We report a facile strategy to prepare chitosan (CS) hydrogels that eliminates the need for chemical crosslinking for advanced biomedical therapies. This approach gives controlled properties to the hydrogels by incorporating a natural bioactive phenolic compound, phloroglucinol (PG), into their microstructure. The adsorption of PG onto CS chains enhanced the hydrogels' antioxidant activity by up to 25 % and resulted in a denser, more entangled structure, reducing the pore size by 59 μm while maintaining porosity above ...
Aufsatz
Solar driven liquid desiccant dehumidification system: Measurements and annual system simulations
(2024-01-17)
Liquid desiccant air conditioning (LDAC) systems are used for dehumidification of air to low dew point temperatures. In the presented study a TRNSYS model of a LDAC unit is developed and validated with laboratory measurements. This model is coupled with a solar thermal system that provides heating water for the regeneration process. With this model dynamic annual system simulations can be carried out to simulate the dehumidification of a building. The solar fraction is evaluated for various infiltration rates of the ...
Aufsatz
Patterns of dissertation dissemination: publication‑based outcomes of doctoral theses in the social sciences
(2024-02-29)
Dissemination of knowledge through the publication of findings is a cornerstone of the academic research system. Doctoral dissertations document the findings made by early-stage researchers during their doctoral studies. However, prior research suggests that dissertations may not be effective in disseminating these findings to the broader community of researchers. We study how knowledge documented in doctoral dissertations is disseminated. Specifically, we investigate which dissertation characteristics and institutional ...
Aufsatz
Influence of effluent particles and particle-bound micropollutants on the removal of micropollutants and UVA₂₅₄ in wastewater effluent ozonation
(2024-01-09)
This study systematically investigated the influence of effluent particles and activated sludge (AS) particles on the removal of micropollutants via wastewater effluent ozonation within typical effluent total suspended solids (TSS) concentrations. A series of batch experiments revealed that particle concentrations up to 30 mg/L had a minor impact on the removal of organic micropollutants (OMPs) in the aqueous phase. Moreover, the reduction of UV absorbance at 254 nm (UVA₂₅₄) was negatively correlated to the level of ...
Aufsatz
Correlation between the activation energy of PLA respectively PLA/starch composites and mechanical properties with regard to differ accelerated aging conditions
(2024-02-22)
Within this research semi-crystalline polylactide and composites with 50 wt.% native potato starch were compounded and injection molded. The material was mechanically characterized by tensile, three-point bending, and Charpy impact tests. These tests were carried out in the freshly molded state and after 332 and 792 h of storage at accelerated temperature or humidity. The respective activation energy was calculated by applying the Flynn-Wall-Ozawa method. The focus of the study was to investigate the correlation ...
Aufsatz
Modelling competitive adsorption of organic micropollutants onto powdered activated carbon in continuous stirred tank reactors for advanced wastewater treatment
(2024-05-21)
This work investigates the validation and application of a competitive model approach for full-scale wastewater treatment plants (WWTP) with external recirculation of partially loaded powdered activated carbon (PAC) for removal of organic micropollutants (OMP). It is based on the ideal adsorbed solution theory (IAST) for multisolute mixtures combined with calibration of fictive organic components and correction of single-solute model parameters for OMP by use of the tracer model (TRM). Adsorption kinetics are represented ...
Aufsatz
Influence of ethylene oxide and gamma irradiation sterilization processes on the degradation behaviour of poly(lactic acid) (PLA) in the course of artificially accelerated aging
(2024-02-10)
To promote the application of bio-based materials in the field of medical technology, it is essential to conduct additional research, focusing on their long-term performance after sterilization. For this purpose, the study examines the aging behaviour of three poly(lactic-acid) (PLA) materials, sterilized with either ethylene oxide or gamma irradiation, over a two years aging period, in accordance with ASTM F1980-21. During these investigations, a direct correlation between moisture absorption and degradation progression ...
Aufsatz
Putting Walkscapes on the Map: GIS-based Visualization for Mobile Methods in Landscape Research
(2024)
The idea of exploring landscapes by walking is historically and socially deeply rooted and fundamental to our modern understanding of landscapes but is often methodologically underrepresented. This paper illustrates that walking can be considered and applied as a method in landscape research. After a brief explanation of walking as a source of knowledge, a selection of mobile methods from literature is explained and their potential in landscape research is outlined. Based on these expla-nations, a new and innovative ...
Aufsatz
Robotically winded full scale timber prototypes
(2024-05-10)
Additive manufacturing is a promising and resource-efficient construction method, applying material only where needed. Demand for these processes in construction is growing, but research into their use in timber construction is limited. The 3DWoodWind project explores additive application methods using thin wood veneer strips. Robotic winding processes can be used to develop wood-based hollow parts with minimal material input and optimised structural properties. This paper presents a modular building system of ...