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Now showing items 1101-1110 of 1153
Aufsatz
Organic Matter Matters—The Imaginary Conductivity of Sediments Rich in Solid Organic Carbon
(2023-12-01)
Solid organic matter (OM) is a biogeochemically relevant constituent of soils and sediments. It also affects sediments' geophysical properties, but is often overlooked in hydro- and biogeophysical approaches for the characterization of the shallow subsurface. Here, we explore the potential of spectral induced polarization (SIP) to delineate OM-rich zones in the subsurface and provide insights into the mechanisms that drive OM-polarization using measurements on both field cores and artificial OM-sand mixtures. Both, ...
Aufsatz
Renewable energy as an alternative source for energy management in agriculture
(2023-07-03)
This study provides a high-level overview of alternative energy sources that can be harnessed to power agricultural operations, focusing on renewable energy technologies. When thinking about the overall economy around the globe, agriculture is vital. Energy is required at each step of production, from fertilizer production to fueling tractors for planting and harvesting. The high energy prices and unpredictable energy market significantly affect the input energy costs. Energy efficiency methods, when properly applied, ...
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 ...