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Model-based Process Generation For Supporting Agile Shop Floor Management In SMEs
No full text546556In recent years, the framework conditions on the Chinese market for machine and equipment manufacturing have changed significantly. By now, products are expected to be customized and at the same time offered at low prices with fast delivery times. Thereby, customer-specific production processes are becoming increasingly important in manufacturing. In addition, German small and medium-sized companies are confronted with a progressively turbulent business environment. For example, Chinese customers expect that orders can still be changed after they had been placed. Hence, companies must be able to identify short-term changes and individual requirements at an early stage. In order to withstand the competitive pressure, alternative courses of action must be created by generating new process variants quickly and reliably. To address this challenge, an approach for the automated generation and realization of processes based on an integrated enterprise model for supporting agile shop floor management as part of an agile process management system is being developed in the German-Chinese joint research project “MAP” and proposed in this paper. Starting with an introduction into the subject matter, the development gap is demonstrated and an approach as well as an early prototype is presented, followed by an outlook on further development in the research project
The Pro-Poor Digitalisation Canvas: Shaping Innovation Towards SDGs 1 and 10
No full text313331With digital technologies playing an ever more important role throughout the world, policy makers, development actors and entrepreneurs have increasingly sought to shape digitalisation’s trajectory in a way to benefit some of the world’s most marginalised communities and progress towards SDGs 1 (‘no poverty’) and 10 (‘reduced inequality’). Moving beyond a widely considered outdated single-issue focus on connectivity, this chapter contributes to the existing research on pro-poor digital development by introducing the Pro-Poor Digitalisation Canvas as an analytical framework for evaluating digital solutions’ developmental potential holistically. The expanded canvas model—spanning across the three dimensions of creation, opportunity and outcome—pays tribute to the multifaceted nature of poverty and inequality and its interplay with digital technologies. As such, it may serve as an important point of reference to innovation managers seeking to leverage innovation for SDGs 1 and 10.Part F45
FFT Based Angle Detection of Fiber Glass Layers
No full text102105We propose an FFT based method to detect the orientation of fiber glass layers. To this end we apply the 2D FFT transform to the radar image data in surface orthogonal coordinates and apply a filtering in frequency space. Finally, we use a CFAR detector to calculate the relevant fiber directions. The method is verified by a test setup, where we use a sample with changing fiber orientation. We observe that the method is able to detect the correct fiber orientation angles up to an error of less than 0.1 degree
AI Agents in Power System Operation: Application Results and Future Potentials
No full textThe increasing complexity of distribution grid management demands innovative solutions for system operators. This paper presents a novel approach for a distribution grid operator assistants using Large Language Models. We implement an LLM agent that autonomously analyzes grid states, identifies problems, and implements corrective measures to maintain grid stability. The agent leverages the ReAct (Reasoning and Acting) framework to combine reasoning capabilities with power system analysis tools to support distribution grid management. First experiments using simulation models demonstrates the agent's ability to consistently resolve line loading issues through grid topology reconfigurations or transformer tap adjustments. The results show that the agent successfully addresses thermal constraints, voltage rise, and reactive power challenges across multiple operational scenarios with high consistency in decision-making. The approach offers a promising solution to the increasing complexity of distribution grid management in the context of renewable energy integration and sector electrification while maintaining transparency in the decision-making process
Re-engineering of optical constants and layer thicknesses from in situ broadband monitoring: an oscillator model approach
No full text866884We present and discuss an in situ optical characterization methodology for calculating individual film thicknesses and optical constants of a multilayer coating. The method is applied to the plasma-ion assisted evaporation of a titania-silica five-layer stack making use of in situ transmittance measurements. In order to guarantee the Kramers-Kronig consistency of the optical constants, a simplified Lorentzian oscillator model has been applied for describing the dispersion of optical constants. Accompanying measurements of the vacuum-air shift of the coatings verify the porosity of the obtained coatings. We emphasize the significance of the application of this characterization technique in order to obtain reliable information from repeatability experiments, necessary to quantify stochastic deposition errors.1
Assessment of the Impact of Nanowarming on Microstructure of Cryopreserved Fibroblast-Containing 3D Tissue Models Using Mueller Polarimetry
No full textWe studied the impact of two different thawing mechanisms on the microstructure of defrosted cryopreserved 3D tissue models using transmission Mueller microscopy and a statistical analysis of polarimetric images of thin histological sections of defrosted tissue models. The cryopreserved 3D tissue models were thawed by using either a 37 °C water bath or radio-frequency inductive heating with the magnetic nanoparticles embedded into the 3D tissue model during the preparation process. Polarimetric measurements were conducted at 700 nm and the acquired Mueller matrices of the samples were post-processed using the differential decomposition and the statistical analysis of the maps of the azimuth of the optic axis. Our results indicate the sensitivity of polarimetry to the changes in thawed tissue morphology compared to that of reference non-frozen tissue. Thus, Mueller microscopy can be used as a fast complementary technique to the currently accepted gold standard methods for the assessment of the cryopreserved tissue microstructure after thawing.101
Development of a Power to Liquids Process for the Production of Dimethyl Ether by Dehydration of Methanol in a Reactive Distillation Column
No full textThe conversion of renewable electricity into chemical energy in so-called "Power-to-X" (PtX) processes is increasingly becoming a central component of the global energy transition. Green hydrogen holds great potential for the sustainable decarbonization of industry and transportation sector, however, hydrogen transport and storage remain challenging. Energy-dense liquid chemical energy carriers in contrast enable an economic large-scale storage and transport of renewable energy over long distances. In this context, dimethyl ether (DME) is a very promising target molecule since it can be used as environmentally benign hydrogen carrier, LPG- and diesel substitute fuel, but also as solvent, refrigerant and propellant.
In this work, the process intensification of the conventional process by applying reactive distillation was studied. This requires shifting the reaction from gas- to liquid phase and significantly lower temperatures. In a catalyst screening using a high throughput batch reactor system, the oversulfonated ion exchange resin Amberlyst 36 and the chlorinated ion exchange resin Treverlyst CAT400 proved to be the most active catalysts under these new reaction conditions. Based on liquid phase kinetic measurements in a fixed-bed profile reactor, a kinetic model valid for the entire operational range reactive distillation was developed. This was achieved by complementing a Langmuir Hinshelwood approach with a dedicated inhibition term to account for the non-linear water inhibition induced by the selective swelling of the resin catalysts. Due to the higher thermal stability, significantly higher reaction rates were reported with the chlorinated resin CAT400.
For the first time in literature, the reactive distillation process with full MeOH conversion was successfully demonstrated with pure and crude MeOH feedstock under industrially relevant conditions using a DN50 pressure distillation column equipped with catalytic packings. Based on 18 experiments, the developed kinetic model could be successfully validated under the process conditions where gas- and liquid phase coexist, and a validated reactive distillation simulation model was developed in Aspen Plus. A system-immanent target conflict between capital and operating expenses was identified when varying the feed mass flow in the experiments. Complementing the process simulation with a factorial economic model allowed to resolve this target conflict and to identify a cost-optimal column sizing. Furthermore, the optimized reactive distillation process concepts with pre-reactor and side-reactor were developed and rigorously optimized. It was found that the developed side-reactor concept presents the most economic and efficient process variant, allowing 39 % cost reduction compared to the conventional gas-phase process. Moreover, it was shown that a plant without external heat demand can be realized when heat integrating MeOH and DME plant
Studies on Protective Coatings for Molding Tools Applied in a Precision Glass Molding Process for a High Abbe Number Glass S-FPM3
No full textPrecision glass molding (PGM) is an efficient process used for manufacturing high-precision micro lenses with aspheric surfaces, which are key components in high-resolution systems, such as endoscopes. In PGM, production costs are significantly influenced by the lifetimes of elaborately manufactured molding tools. Protective coatings are applied to the molding tools to withstand severe cyclic thermochemical and thermomechanical loads in the PGM process and, in this way, extend the life of the molding tools. This research focuses on a new method which combines metallographic analysis and finite element method (FEM) simulation to study the interaction of three protective coatings—diamond-like carbon (DLC), PtIr and CrAlN—each in contact with the high Abbe number glass material S-FPM3 in a precision glass molding process. Molding tools are analyzed metallographically using light microscopy, white light interferometry, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The results show that the DLC coating improved process durability more than the PtIr and CrAlN coatings, in which the phenomenon of coating delamination and glass adhesion can be observed. To identify potential explanations for the metrological results, FEM is applied to inspect the stress state and stress distribution in the molding tools during the molding process.13
Ka-Band Low-Noise-Amplifier MMIC in a 70-nm GaN-on-SiC Technology
No full textThis letter presents the design and characterization of a Ka-band low-noise-amplifier (LNA) monolithic microwave integrated circuit (MMIC) implemented on a 70-nm gallium nitride (GaN)-on-SiC high-electron-mobility transistor (HEMT) process. The three-stage LNA combines microstrip and coplanar technologies to minimize the losses before the first transistor and shows an average small-signal gain of 25±2.5 dB and an average noise figure (NF) of 1.3 dB from 27 to 40 GHz, with a dc power consumption of 0.311 W. The MMIC was also subject to large signal testing, exhibiting an output power at 1-dB gain compression of 9.9 dBm at 35 GHz and surviving an overdrive continuous wave signal at 26 GHz with a power of up to +25 dBm with no significant S-parameter performance degradation. To the best of our knowledge, this is the first demonstration of a Ka-band MMIC LNA in GaN with average NF 1.3 dB from 27 to 40 GHz.Online Firs
Decoupling of thermal and mechanical load with fiber optic sensors for in-situ battery monitoring
No full textThis work introduces a novel approach for in-situ monitoring of temperature, strain and electrode half-cell potentials within lithium-ion battery cells using distributed fiber-optic sensing based on Optical Frequency Domain Reflectometry combined with a Reference electrode. By embedding two co-located optical fibers with different core dopants, the method enables the decoupling of thermal and mechanical effects through calibrated differences in temperature sensitivity. By using a conductive fiber coating as a Reference electrode the measurement of half-cell potentials is combined with the optical measurement. The fibers were successfully integrated into a functional LIB pouch cell and validated through controlled thermal testing. This technique enables fully embedded diagnostics, offering a significant advancement for real-time thermal management and safer fast-charging strategies in future battery systems