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Aufsatz
Towards collaborative planning: deliberative knowledge utilisation and conflict resolution in urban regeneration in South China
(2024-03-22)
Urban regeneration in post-reform China has become a fertile ground for the transition towards collaborative planning, which serves as a powerful tool for managing conflicts and addressing complex urban challenges. This article aims to delve into the micro-level processes that underpin the emergence of collaborative planning in practical urban regeneration projects in China. By shedding light on these micro-level processes of conflict resolution, we aim to provide a deeper understanding of how collaborative planning ...
Aufsatz
Labour relations and working conditions of workers on smallholder cocoa farms in Ghana
(2023-06-16)
The millions of farm workers in the Global South are an important resource for smallholder producers. However, research on their labour organisation is limited. This article focuses on smallholder farm workers in Ghana’s cocoa sector, drawing on insights from qualitative interviews and the concept of bargaining power. We review the labour relations and working conditions of two historical and informally identified labour supply setups (LSSs) in Ghana’s cocoa sector, namely, hired labour and Abusa, a form of ...
Aufsatz
On the Influence of Surface Hardening Treatments on Microstructure Evolution and Residual Stress in Microalloyed Medium Carbon Steel
(2020-06-09)
Tailoring surface properties is a key to superior performance of components subjected to fatigue loadings in application. Process–microstructure–property relationships have to be established to allow for optimization of techniques employed for surface treatments such as deep rolling and induction hardening. Although both techniques are employed widely in industrial application, studies examining microstructure evolution and residual stress states for a single material in a comparative manner are missing. Amongst ...
Aufsatz
Influence of Microstructure and Defects on Mechanical Properties of AISI H13 Manufactured by Electron Beam Powder Bed Fusion
(2021-08-04)
Electron beam powder bed fusion (E-PBF) is a well-known additive manufacturing process. Components are realized based on layer-by-layer melting of metal powder. Due to the high degree of design freedom, additive manufacturing came into focus of tooling industry, especially for tools with sophisticated internal cooling channels. The present work focuses on the relationships between processing, microstructure evolution, chemical composition and mechanical properties of a high alloyed tool steel AISI H13 (1.2344, ...
Aufsatz
Evaluation of extremely steep residual stress gradients based on a combined approach using laboratory-scale equipment
(2021-11-30)
Surface treatments characterized by rapid heating and cooling (e.g. laser hardening) can induce very steep residual stress gradients in the direct vicinity of the area being treated. These gradients cannot be characterized with sufficient accuracy by means of the classical sin2Ψ approach applying angle-dispersive X-ray diffraction. This can be mainly attributed to limitations of the material removal method. In order to resolve residual stress gradients in these regions without affecting the residual stress equilibrium, ...
Aufsatz
On the Impact of Build Envelope Sizes on E-PBF Processed Pure Iron
(2021-11-17)
In additive manufacturing, the thermal history of a part determines its final microstructural and mechanical properties. The factors leading to a specific temperature profile are diverse. For the integrity of a parameter setting established, periphery variations must also be considered. In the present study, iron was processed by electron beam powder bed fusion. Parts realized by two process runs featuring different build plate sizes were analyzed. It is shown that the process temperature differs significantly, ...
Aufsatz
A Novel Thermo-Mechanical Processing Route Exploiting Abnormal Grain Growth in Heusler-Type Co–Ni–Ga Shape Memory Alloys
(2022-10-04)
Heusler-type Co–Ni–Ga shape memory alloys attracted significant scientific attention owing to excellent superelasticity in single-crystalline state. However, due to pronounced anisotropy, polycrystalline Co–Ni–Ga suffers from transformation-induced constraints at grain boundaries and, thus, premature failure upon thermo-mechanical loading. The present study reports on a novel thermo-mechanical processing route. Hot rolling followed by solution-annealing promotes abnormal grain growth, eventually leading to high-performance ...
Aufsatz
Post-Carolingian Geographies of North and West in Rodulfus Glaber
(2023-12-14)
This article evaluates the geographical consciousness of north and west found in the Five Books of the Histories by the eleventh-century Burgundian monk Rodulfus Glaber. In contrast with dominant approaches to medieval geography that have informed prior commentators, who have focused on ideas of Europe or the opposition of east and west, it argues that we must situate Glaber's spatial consciousness first and foremost in the lineage of Carolingian and post-Carolingian conceptions of the north. Focusing especially on ...
Aufsatz
Hot Work Tool Steel Processed by Laser Powder Bed Fusion: A Review on Most Relevant Influencing Factors
(2021-03-26)
As a representative of a common carbon-bearing hot work tool steel AISI H13 is in focus of the present review paper. Most relevant details for processing of AISI H13 by laser powder bed fusion (L-PBF) are systematically investigated. Three common stages of process parameter development and material assessment, respectively, are in focus: general processibility, process refinement, and deduction of process–microstructure–property relations, i.e., understanding of the interplay of relevant elementary mechanisms. On the ...
Aufsatz
CuCrZr processed by laser powder bed fusion — Processability and influence of heat treatment on electrical conductivity, microstructure and mechanical properties
(2021-06-16)
CuCrZr parts were fabricated by laser beam powder bed fusion (LB-PBF) technique and subjected to different heat treatments. As a result, four different conditions were considered for further investigations, that is, the as-built condition, conditions of maximum hardness (MH) and maximum electrical conductivity (MC), and a condition representing a compromise between hardness and conductivity (H&C). Microstructural evolution and performance under monotonic and cyclic loading were studied. Fracture surfaces revealed ...