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Nachweis der Betriebsbewährtheit von PLT-Feldgeräten anhand alternativer Datenquellen
No full textIn the chemical-pharmaceutical industry, also known as the process industry, process control technology safety devices (PCT safety devices) use automation technology to ensure that production plants (process plants) are brought to a safe state when re-quired. In accordance with IEC 61511, all PCT field devices used in a PCT safety loop must be provided with a proof of operational reliability, irrespective of the existence of a safety integrity level classification in accordance with IEC 61508. The standards IEC 61511 and VDI/VDE 2180 for functional safety in the process industry refer to the NAMUR Recommendation 130 (NE 130), which was amended in 2023, as a possible way of proving operational reliability. In contrast to the previous version, this amended NE 130 enables a case-by-case assessment and thus an applicative proof of operational reliability. In the current report by the Commission for Plant Safety (KAS) of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) on the results of expert inspections in accordance with Section 29b of the Federal Immission Control Act from 2022, the chemical plants category had a defect rate of of 43.8%. The criteria for a deficiency are defined based on the KAS 36 report (see, e.g., the version published 2024). Deviations in the design and documentation of PCT safety devices were listed as one of the main causes of this high defect rate of errors. This dissertation uses a qualitative study to prove that this defect rate also relates to the proof of operational reliability. Based on the V-model in relation to IEC 61508 and on the “Internet of Production” model (IoP) of RWTH Aachen University, a concept for data-based proof of operational reliability is developed. The concept is divided into a prospective information model as a guideline for structuring device data and a retrospective approach for evaluating heterogeneous brownfield data. The case-by-case approach introduced with the amendment of NE 130 published in 2023 supports the proof of operational reliability when only small data sets are available and is therefore also suitable for operators based of small plants with a small number of devices. The result of the present work is a proof of the effectiveness of this concept. In the retrospective approach, input data are structured in a script-based manner and the results can be easily evaluated by experts. In addition to the advantage of being able to process large amounts of field device data in short time, the concept has a higher accuracy and reliability due to the use of statistical data compared to a manual approach
Beam management and resource allocation for 5G-and-beyond millimeter-wave cellular networks
No full textThe ever-growing mobile data and user demands are creating unprecedented challenges for cellular networks. To meet the capacity demands, next generation networks need to explore heterogeneous radio access technologies and new spectrum opportunities beyond the current sub-6 GHz bands. An example of this are the spectrum-rich millimeter-wave (mm-wave) bands for 5G new radio (NR) operation in frequency range 2 (FR2), offering large bandwidth for commercial licensed and unlicensed deployments and several gigabits per second (Gbps) data rates. Ongoing efforts on the design and operation of 5G-NR FR2 networks come with many practical challenges, which have hindered widespread adoption since their introduction in the first 5G-NR Release 15 in 2017. This thesis addresses two key enablers of 5G-and-beyond FR2 cellular networks, namely beam management and resource allocation. Beam management is essential for providing robust multi-Gbps connectivity via directional beamforming and overcoming the effects of signal attenuation, dynamic blockages and beam misalignment. Resource allocation is essential for efficient use of the wider channels and the support of different beamforming, multiplexing and frequency band configurations. Efficiently sharing the network capacity in 5G-and-beyond FR2 is thus fundamentally different from current sub-6 GHz FR1 networks, and accordingly requires new approaches that jointly consider beam management and resource allocation.We address the posed challenges with the following contributions. (1) We conduct two large-scale outdoor mm-wave phased antenna array measurement campaigns, totaling over 421,000 individual measurements in Aachen and over 50,000 in Langenfeld, respectively. Our measurement evaluation reveals a limited number of 2–8 beam pair link (BPL) opportunities per position, and significant losses in the achievable data rate for small-scale misalignment in the order of the beamwidth, and large and irregular variations for large-scale misalignment due to the irregular phased antenna array patterns. (2) We demonstrate that current mm-wave beamsteering algorithms, when tested using outdoor phased antenna array measurements, perform far from optimal and worse than originally reported, suggesting that more robust approaches must be designed that intelligently adapt to the site-specific mm-wave channel and the real characteristics of commercially-viable phased antenna arrays. (3) We show that mm-wave statistical channel models are not able to fully capture the spatial and angular distribution of the feasible BPL opportunities. Ray-tracing, as an alternative deterministic channel modeling approach, is shown to be able to provide reliable channel data, for which it is crucial to accurately model the real codebook-based antenna patterns, whereas a basic effort is sufficient for modeling the site-specific 3D environment. (4) We propose flexRLM, a 5G-NR-compliant flexible framework for joint beam management and load-balancing, and demonstrate its superior performance over default 5G-NR in terms of link quality and stability, handover delays and load-balancing. To enable detailed validation, we develop the first full-stack 5G-NR beam management simulation framework in ns-3, which implements the full downlink beam management control including initial access, radio link monitoring, handover coordination and radio link failure detection and recovery. Our end-to-end networking study demonstrates that the site-specific mm-wave channel variations can be overcome on the 5G-NR network side via more agile beam management approaches such as flexRLM. (5) We propose IABA, a 5G-NR-compliant interference-aware resource allocation that jointly considers interference cancellation and spatial BPL allocation for interference management in multi-user 5G-and-beyond FR2 networks. We show that IABA significantly outperforms default 5G-NR under various codebook-based and hybrid beamforming network configurations, highlighting the need for additional interference mitigation via spatial BPL allocation beyond solely considering interference cancellation in practical 5G-and-beyond FR2 networks
Entwicklung von Personas als Methode zur Stärkung der interdisziplinären Zusammenarbeit im Großforschungsverbund
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An evaluation of speech therapy care in the surrounding area of an interdisciplinary cleft lip and palate tertiary care center
No full textVinyltriflimide als funktionales Chamäleon : Untersuchung der stabilisierenden Eigenschaften von Trifluoromethylsulfonyl-Substituenten in (photochemischen) Synthesen
No full textVinyl triflimides are a novel class of compounds that can serve as versatile building blocks in the synthesis of nitrogen-containing compounds due to their highly electron-withdrawing trifluoromethylsulfonyl groups. This dissertation investigates the reactivity and potential applications of vinyl triflimides in four projects, in which their versatility is demonstrated by means of various reactivities:1) By applying the assisted vinyl cation formation method, developed in the Niggemann working group, a stereo- and regioselective synthesis of bromovinyl triflimides was achieved, in which the nucleophilic addition to halovinyl cations is controlled and extends the previously limited synthesis possibilities of halogenated alkenes. 2) The reactivity of vinyl triflimides was investigated in photochemical processes. In triplet-triplet energy transfer reactions, they show their potential as a class of sulfonamides that undergo homolytic cleavage of the N ̶ S bond by visible light. This method overcomes the previous limitations of synthesis procedures restricted to high-energy UV light and enables the efficient one-pot two-step synthesis of α-quaternary-β-trifluoromethylated amines without the addition of external reagents due to the duality of vinyl triflimide as substrate and trifluoromethylation reagent. 3) Another photochemical approach demonstrates the versatility of vinyl triflimides in photoredox processes, in which they are reduced to trifluoromethylsulfonimines and reacted with stable boron complexes (NHC boranes) to form stable and isolable N-borylamides. These stabilized substrates overcome the problems of hydrolysis and air sensitivity encountered with compounds containing B-N bonds in traditional syntheses. 4) The stabilizing properties of trifluoromethylsulfonyl groups have also been exploited for the synthesis of imine phosphorylides, a class of compounds that has been little explored to date. Vinyl triflimides present themselves as compounds with unique properties, both in photochemical processes and in the synthesis of difficult-to-access substrate classes. A mechanistic focus of the work provides explanations for the special reactivities and possible applications of this substance class
Biocatalysis in organic environments and nanoconfined flow reactors
No full textBiocatalysis utilizing enzymes or whole cells has emerged as a sustainable route for chemical synthesis. The sustainability and efficiency of biocatalysts have been significantly improved through immobilization strategies. These strategies have been applied into various biocatalytic processes, such as continuous-flow or non-aqueous catalysis, facilitating their applications in diverse environments. However, inadequate biocatalytic efficiency in the continuous-flow reactor was often resulted from insufficient enzyme immobilizations and from extreme differences in dimensions between nano-sized enzymes and reaction space in porous supports. Additionally, the stability of biocatalysts under industrial conditions is problematic, especially in the presence of prevalent organic solvents, which can compromise their functionalities or even denature enzymes. Addressing these challenges is crucial for widespread applications of biocatalysis in industry. In the first chapter, we demonstrate a general-applicable and robust approach for the fabrication of a high-performance enzymatic continuous-flow reactor via integrating well-designed scalable isoporous block copolymer (BCP) membranes as carriers with an oriented and productive immobilization employing material binding peptides (MBPs). Densely packed uniform enzyme-matched nanochannels of well-designed BCP membranes endow the desired nanoconfined environments towards a productive immobilized phytase. Tuning nanochannel properties can further regulate the complex reaction process and fortify the catalytic performance. The synergistic design of enzyme-matched carriers and efficient enzyme immobilization empowers an excellent catalytic performance with > 1 month operational stability, superior productivity, and a high space-time yield (1.05 × 105 g L−1 d−1) via a single-pass continuous-flow process. The obtained performance makes the designed nano- and isoporous block copolymer membrane reactor highly attractive for industrial applications.In the second chapter, the ‘synthetic biofilm’ stimulated hydrogel bioreactor (C-gels) with millimeter scale were constructed by encapsulating E. coli whole cells harboring P450 BM3 M2 within Ca(II)-alginate hydrogels for o-hydroxylation of mono-substituted benzenes (i.e., toluene) in pure- and co-organic solvents. Compared to free cells, the biocompatible Ca(II)-alginate hydrogel matrix is capable of protecting cells with an 8-fold increase in catalytic efficiency (> 4h), a 2.7-fold improved productivity, and prolonged cell survivability (> 1h) in the neat substrate of toluene. Interestingly, Ca(II)-alginate hydrogels characteristics, internal aqueous, Ca(II) microenvironment, and hydrophlicity can further modulate the biocatalytic performance in toluene. Encouragingly, the engineered C-gels displayed improved organic solvent resistance and region-selective catalysis with intact porouos structures in a variety of organic co-solvents (e.g., MTBE, Chloroform, 1-Heptanol) demonstrating the versatility of the Ca(II)-alginate hydrogel-based bioreactor. The strategy of encapsulating whole cells in ionic crosslinked C-gels provides a blueprint regarding the design of the next generation of ‘synthetic biofilm’ for highly efficient biocatalysis in pure- or co-organic solvents. Ca(II)-alginate as ‘synthetic biofilm’ might be employed as “compatibilizers” to address the contradiction between insoluble substrates and aqueous favorable living cells. Meanwhile, other investigated strategies (e.g., hyaluronic acid-based single-cell encapsulations, phenol-biopolymer-based multi-cell encapsulations, and SpyCatcher/SpyTag-based self-crosslinking) showed non-obvious enhancement on biocatalysis due to the limited knowledge to comprehensively optimize these complicated integrated systems.In summary, two robust biocatalysis platforms intergrating immobilized enzymes and whole cells with materials were well-designed in this dessertation to empower continuous-flow and non-aqueous bioreactors. Designed enzyme-matched isoporous membrane flow reactors and organic resistant ‘synthetic biofilm’ reactors showcase the advantages in stabilizing biocatalysts, increasing activity, and extending operational lifespan under industrial conditions, which are consistent with green chemistry principles to reduce energy consumption and to minimize chemical use. These developed biohybrid plateforms have the great potential to pave the way for the next generation of biocatalysis with broader industrial applicability and sustainability
