Analyse eines digitalen Zwillings zur zeitkontinuierlichen Batchoptimierung in der Halbleiterfertigung

Motivated by the ongoing growth in demand for microchips, high production costs and the complex interplay of human, machine, material and method (4M), suppliers strive to develop more advanced production planning and control regimes for semiconductor production. Batching decisions often dramatically influence the overall performance of wafer fabs in terms of capacity utilization, due date compliance, cycle time and variability. To optimize such processes, we present an integrated testbed for batch formation optimization. Using a simulation of multiple semiconductor work centers, we explore how to optimize work in progress (WIP) flow with a continuous real-time scheduler and previously published batch formation heuristics. The proposed solver is designed to only optimize capacity-limited operations. By considering real-world operations requirements and semiconductor process specifics such as qualification criteria and re-entrance in our model, we demonstrate how to realize significant throughput gains. We explore and demonstrate the developed digital twin through a powerful BI frontend for historical analysis and real-time shop floor monitoring

Maßstäbe demokratischer Legitimation

The concept of democratic legitimization is used in various disciplines and also in different legal contexts. However, it is regularly not a matter of one and the same legal standard; rather, German constitutional law and EU primary law appear to contain very different approaches. There are also certain shifts in discourse between jurisprudence and legal scholarship. The thesis differentiates methodologically and disciplinarily in order to put the different positions in relation to each other and to gain a better overview of the discourse.PublishedDer Begriff der demokratischen Legitimation wird in verschiedenen Fachdisziplinen und auch in verschiedenen rechtlichen Kontexten verwendet. Dabei handelt es sich allerdings regelmäßig nicht um ein und denselben rechtlichen Maßstab, vielmehr zeigen das deutsche Verfassungsrecht und das Primärrecht der EU teilweise sehr unterschiedliche Ansätze. Auch zwischen Rechtsprechung und der Rechtswissenschaft zeigen sich gewisse Diskursverschiebungen. Die Arbeit nimmt eine methodische und disziplinäre Differenzierung vor, um die unterschiedlichen Positionen zueinander ins Verhältnis zu setzen und einen besseren Überblick über den Diskurs zu gewinnen

Editorial : Advances in the spatial and temporal evolution of oceanic arc-backarc systems

Non peer reviewe

Vulkanismus und erzbildende Prozesse an Subduktionszonen

An Inselbogenvulkanen können sich im Untergrund, nahe des entgasenden Magmas, Lager­stätten für ökonomisch interessante Metalle wie Kupfer, Molybdän oder Gold bilden

Microbial recovery of metals from solids

A variety of both lithotrophic and organotrophic microorganisms are known to mediate the mobilization of various elements from solids mostly by the formation of inorganic and organic acids. Under appropriate environmental conditions, metals are solubilized and extracted from metal-rich materials in subsurface ecosystems by the action of bacteria and fungi. In mine tailings or landfills microbial metal leaching represents a potential environmental hazard. However, these microbial activities can be successfully applied in the industry for the recovery of metals from solid materials such as ores or incineration residues. Microbial leaching processes are currently used for the winning of gold and copper from low-grade ores (‘bioleaching'). Solid industrial waste materials such as fly ash, sludges, or dust might also be microbially treated to recover metals for the re-use in metal-manufacturing industries. Bioleaching allows the cycling of metals by a process close to natural biogeochemical cycles reducing the demand for resources such as ores, energy, or landfill spac

Geochemistry of volcanic glasses from the Louisville Seamount Trail (IODP Expedition 330): Implications for eruption environments and mantle melting

Volcanic glasses recovered from four guyots during drilling along the Louisville Seamount Trail, southwest Pacific, have been analyzed for major, trace, and volatile elements (H2O, CO2, S, and Cl), and oxygen isotopes. Compared to other oceanic island settings, they are geochemically homogeneous, providing no evidence of the tholeiitic stage that characterizes Hawaii. The degrees and depth of partial melting remained constant over 1–3 Ma represented by the drill holes, and along-chain over several million years. The only exception is Hadar Guyot with compositions that suggest small degree preferential melting of an enriched source, possibly because it erupted on the oldest and thickest lithosphere. Incompatible element enriched glass from late-stage volcaniclastics implies lower degrees of melting as the volcanoes moved off the melting anomaly. Volcaniclastic glasses from throughout the igneous basement are degassed suggesting generation during shallow submarine eruptions (<20 mbsl) or as subaerial flows entered the sea. Drill depths may no longer reflect relative age due to postquench downslope movement. Higher volatile contents in late-stage volcaniclastics indicate submarine eruptions at 118–258 mbsl and subsidence of the edifices below sea level by the time they erupted, or generation in flank eruptions. Glass from intrusion margins suggests emplacement ∼100 m below the surface. The required uplift to achieve these paleo-quench depths and the subsequent subsidence to reach their current depths exceeds that expected for normal oceanic lithosphere, consistent with the Louisville melting anomaly being <100°C hotter than normal asthenosphere at 50–70 Ma when the guyots were erupted. Key Points: - Louisville glasses show remarkable temporal geochemical homogeneity - All recovered Louisville glasses are variably degassed - Louisville melting anomaly was <100°C hotter than normal asthenospher