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Aufsatz
Bedeutende Städte jenseits der Metropolen? Regiopolen und ihre Rolle im deutschen Städtesystem
(2022-11-10)
Regiopolen und Regiopolregionen erfahren eine bisher kaum dagewesene Aufmerksamkeit in der deutschen Raumordnungspolitik. Neben der Förderung des deutschen RegioPole-Netzwerks durch den Bund sind Regiopolen und Regiopolregionen bereits in mehreren Raumordnungsplänen ausgewiesen. Im wissenschaftlichen Diskurs werden Regiopolen hingegen kaum aufgegriffen. Das zeigt sich insbesondere daran, dass zwar mit Dimensionen wie Stadtgröße (mehr als 100.000 Einwohner) und räumlicher Lage (außerhalb der Metropolregionen) operiert ...
Aufsatz
Water quality footprint of agricultural emissions of nitrogen, phosphorus and glyphosate associated with German bioeconomy
(2023-11-02)
Fertiliser and pesticide application can cause extensive environmental damage. We use the water quality footprint to express nitrogen, phosphorus and glyphosate emissions from agriculture in volumes of water needed to virtually dilute pollution and apply the approach to agricultural imports for the German bioeconomy in 1995 and 2020. In total, the virtual German water quality footprint corresponds to 90 times the volume of Lake Constance. If water pollution had to be eliminated by dilution in export countries supplying ...
Aufsatz
Systems methods for analyzing trade‑offs between food security and conserving biodiversity
(2023-04-15)
The endeavor for greater food security has caused trade-offs between increasing agricultural production and conserving habitat of threatened species. We take a novel approach to analyze these trade-offs by applying and comparing three systems methods (systems diagrams, influence matrices, and land use modeling) in a case study of Uganda. The first two methods were used to scope out the trade-off system and identify the most important variables influencing trade-offs. These variables were agricultural yield, land ...
Aufsatz
Optimization of the bicinchoninic acid assay for quantifying carbohydrates of soil extracellular polymeric substances
(2023-12-23)
Background and aims
The bicinchoninic acid (BCA) method was not yet applied on soil extracts of extracellular polymeric substances (EPS) to quantify polysaccharides, although this might be possible by introducing a cleavage step to produce monosaccharides. A pre-extraction with CaCl₂ to remove interfering substances is usually performed before extracting EPS. The main objective of this study was to optimize the BCA assay for total carbohydrates quantification by applying a hydrolysis step to the EPS extracts, while ...
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
The chronos of class conflict. The relevance of the temporal dimension in conflicts related to labour migration
(2023-10-13)
In recent migration research temporality has become a prominent figure. Focussing on temporality allows to shed light on some aspects of labour mobility that enlighten our understanding of work-related conflicts. Especially with view to labour market inclusion, migrants often experience the (assumed) temporal limitation and unpredictability of migration projects, work and residence permits, as well as employment relationships. Correspondingly, labour policies, sector-specific company structures and management techniques ...
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 ...