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Springback and wrinkle control in deep drawing of paperboard with segmented blank holder
No full textDeep drawing of paperboard enables highly productive forming processes for packaging products made of a recyclable material. However, the inherent anisotropy and low elasticity of paperboard pose challenges for deep drawing processes, especially resulting in direction-dependent springback and wrinkling of the formed parts. This paper presents an approach that addresses these challenges by using a segmented blank holder. The goal is to improve component quality both locally and globally by applying different blank holder forces to each segment. To this end, a concept is presented for a pneumatically driven segmented blank holder, along with two different forming geometries. Deep-drawing tests with segment-specific blank holder force distributions were performed and compared with those using a conventional blank holder. Although segmentation of the blank holder did not improve performance when the force per segment was identical, an uneven force distribution was able to improve forming in terms of shape accuracy and wrinkle pattern. Depending on the selected force distribution, significant compensation for springback anisotropy and the creation of wrinkle-free straight areas was shown to be possible
Author-in-the-Loop Response Generation and Evaluation: Integrating Author Expertise and Intent in Responses to Peer Review
No full textAuthor response (rebuttal) writing is a critical stage of scientific peer review that demands substantial author effort. Recent work frames this task as automatic text generation, underusing author expertise and intent. In practice, authors possess domain expertise, author-only information, revision and response strategies--concrete forms of author expertise and intent--to address reviewer concerns, and seek NLP assistance that integrates these signals to support effective response writing in peer review. We reformulate author response generation as an author-in-the-loop task and introduce REspGen, a generation framework that integrates explicit author input, multi-attribute control, and evaluation-guided refinement, together with REspEval, a comprehensive evaluation suite with 20+ metrics covering input utilization, controllability, response quality, and discourse. To support this formulation, we construct Re^3Align, the first large-scale dataset of aligned review--response--revision triplets, where revisions provide signals of author expertise and intent. Experiments with state-of-the-art LLMs show the benefits of author input and evaluation-guided refinement, the impact of input design on response quality, and trade-offs between controllability and quality. We make our dataset, generation and evaluation tools publicly available
Analysis of local thermochemical states in turbulent H2-air multi-mode flames by Raman/Rayleigh spectroscopy
No full textThe effects of turbulent mixing and mixture inhomogeneity on the flame structures of turbulent hydrogen–air multi-mode flames stabilized on a modified Darmstadt multi-regime burner are investigated in this study. Near-simultaneous one-dimensional Raman/Rayleigh and two-dimensional Rayleigh scattering measurements are used to quantify the internal flame structures and flame topologies, whereas simultaneous two-dimensional laser-induced fluorescence of hydroxyl radicals and particle image velocimetry are performed to characterize the macroscopic flame structures and flow fields. Quantitative multi-scalar data, including temperature and major species mole fractions, combined with two-dimensional flame topologies, enable characterization of the local thermochemical states. The examined hydrogen–air multi-mode flames consist of a lifted central jet reaction zone, a primary recirculation zone, a secondary recirculation zone, and an outer reaction zone. Quantitative multi-scalar results reveal an intense jet flame reaction zone characterized by local temperature and water mole fraction peaks. These burning behaviors, which differ from previously investigated methane–air multi-mode flames, are attributed to the higher reactivity and the wider flammability range of hydrogen. Global thermochemical state data indicate significant different reaction trajectories in flames with either different turbulent mixing levels or mixture inhomogeneities. Instantaneous thermochemical states conditioned on the central jet flame front demonstrate the variety of reaction trajectories spanning a wide range of equivalence ratios in the flame with the highest initial jet equivalence ratio. Combined with the heat release rate results derived from one-dimensional simulations, the example single-shot data suggest premixed and stratified combustion modes near the jet flame stabilization position. Local thermochemical state results indicate that an increasing air flow velocity from a surrounding slot increases the jet flame lift-off height and modifies the local equivalence ratio distribution, while a higher jet equivalence ratio promotes a broader diversity of reaction trajectories
Experimental investigation of particle-flow-chemistry interactions
No full textThe combustion of solid particulate fuels involves the interplay of particle phase, fluid flow, and thermochemistry, where investigating and quantifying the influence of each aspect of this interaction triangle is essential to modelling and understanding the combustion processes. This chapter presents an in-depth experimental investigation of particle-flow-chemistry interactions in solid fuels, with a focus on high-volatile bituminous coal and biomass. The fundamental physico-chemical processes of solid fuel combustion are outlined, illustrated by the behaviour of a single solid fuel particle in a hot gaseous environment. Two experimental configurations are described: a laminar flat flame burner for controlled particle-particle interaction studies, and a turbulent hot gas test rig for the investigation of the interplay of turbulent carrier flows and particulate fuels. Various optical diagnostic techniques were advanced and applied to obtain detailed data on particle and gas-phase interactions. The experimental investigations provide valuable insights and unique data that are essential for validating and improving combustion models, thus contributing significantly to the understanding and modelling of solid fuel combustion
RockNet: Distributed Learning on Ultra-Low-Power Devices
No full textAs Machine Learning (ML) becomes integral to Cyber-Physical Systems (CPS), there is growing interest in shifting training from traditional cloud-based to on-device processing (TinyML), for example, due to privacy and latency concerns. However, CPS often comprise ultra-low-power microcontrollers, whose limited compute resources make training challenging. This article presents RockNet , a new TinyML method tailored for ultra-low-power hardware that achieves state-of-the-art accuracy in timeseries classification, such as fault or malware detection, without requiring offline pretraining. By leveraging that CPS consist of multiple devices, we design a distributed learning method that integrates ML and wireless communication. RockNet leverages all devices for distributed training of specialized compute efficient classifiers that need minimal communication overhead for parallelization. Combined with tailored and efficient wireless multi-hop communication protocols, our approach overcomes the communication bottleneck that often occurs in distributed learning. Hardware experiments on a testbed with 20 ultra-low-power devices demonstrate RockNet ’s effectiveness. It successfully learns timeseries classification tasks from scratch, surpassing the accuracy of the latest approach for neural network microcontroller training by up to 2x. RockNet ’s distributed ML architecture reduces memory, latency and energy consumption per device by up to 90% when scaling from one central device to 20 devices. Our results show that a tight integration of distributed ML, distributed computing, and communication enables, for the first time, training on ultra-low-power hardware with state-of-the-art accuracy
Thermocapillary convection and interface deformation in evaporating liquid films on a structured surface
No full textIn this study, the evolution of thin hydrofluoroether (HFE) films that evaporate on sinusoidally structured copper walls while experiencing thermocapillary and, in mixtures, solutocapillary stresses, is investigated experimentally. An open cell equipped with a chromatic--confocal line sensor and Schlieren imaging provides time-resolved liquid--gas interface deformation profiles for pure HFE-7100 films and for HFE-7100/HFE-7500 mixtures. Experiments show that the spatially averaged liquid--gas interface location decreases linearly with time, so that the average evaporation flux remains constant for each wall temperature. The interface adopts a quasi-steady cosine shape whose amplitude increases with increasing evaporation flux. In the investigated binary mixtures, thermo- and solutocapillary stresses oppose each other. Thermocapillarity remains dominant, yet progressive depletion of the volatile HFE-7100 leads to attenuation of the deformation, so that the amplitude approaches the pure HFE-7500 limit. The measured deformation of the pure HFE-7100 film is compared with predictions of a simple model based on long-wave approximation
Chromatin remodelling subunit SMARCB1 is implicated in dendrite development and complex brain functions
No full text3D-gedruckte freitragende Betondecke
No full textIm Sommersemester 2025 startete am Institut für Konstruktives Gestalten und Baukonstruktion (KGBauko) der TU Darmstadt ein wegweisendes Forschungs- und Entwicklungsprojekt im Bereich des 3D-Betondrucks (3D Concrete Printing, 3DCP). Das Projekt wurde in enger Kooperation mit Sika Deutschland, der Riedel Bau Gruppe und Staikos 3D durchgeführt und steht exemplarisch für die zunehmende Verzahnung von digitaler Planung, additiver Fertigung und nachhaltiger Baukultur
Direct determination of the Fe3+/2+ charge-transition level in BaTiO3 and isovalently substituted Ba0.82Ca0.18Ti0.92Zr0.08O3 by x-ray photoelectron spectroscopy
No full textCharge-transition levels of dopants in oxides and other semiconductors are key factors affecting a wide range of material properties. Despite their importance, only very few charge-transition levels are known quantitatively. This work aims to validate the direct experimental determination of charge-transition levels of dopants in oxides by means of x-ray photoelectron spectroscopy (XPS). The approach is used to derive the energy level associated with the Fe 3 + / 2 + transition, which is determined as 2.45 ± 0.05 eV and 2.65 ± 0.05 eV above the valence band maximum of BaTiO 3 and Ba 0.82 Ca 0.18 Ti 0.92 Zr 0.08 O 3, respectively. The former agrees with thermogravimetric and electric measurements. The results consolidate that XPS is a versatile and reliable technique to experimentally determine charge-transition levels, which can be used to reveal systematic dependencies on concentration, temperature, and host material. It is further demonstrated that high-temperature near-ambient pressure XPS performed at a synchrotron is ideally suited for the determination of charge-transition levels
Simultaneous Bacteria Sensing and On-demand Antimicrobial Peptide Release
No full textA material able to simultaneously sense a bacterial presence and to on-demand release antimicrobial peptides (AMP) in a tunable amount was developed. Simultaneous sensing and release were achieved by the combination of a bacteria-sensing hydrogel with antimicrobial peptide-carrying mesoporous silica particles or coatings. The mesoporous silica with a mesopore diameter of 22 nm was functionalized with a covalently grafted green light-sensitive linker to which antimicrobial peptides were covalently attached. The gelatin-based hydrogel, which contains C14R functionalized mesoporous silica particles, is designed to respond to bacteria presence as it may occur e.g. in a wound's microbiological environment.
In the presence of bacteria and 0.1 % trypsin, a protease enzyme simulating bacterial presence, the hydrogel, deposited in a donut shape, undergoes a shape loss as the bacteria cleave cross-linking bonds within the hydrogel. When observing hydrogel shape loss after 2 hours as a readout of a bacterial infection subsequent irradiation triggers the release of antimicrobial peptides on demand with adjustable concentration-time profiles. The sensing and on-demand release are integrated into commercially available wound dressing fabrics demonstrating an application proof-of-concept. Characterization using ATR-IR spectroscopy, TGA, and BCA validate the successful fabrication and release. The H1.6P composite released antimicrobial agents, reaching concentrations of up to 298 μg/mL at pH 7.4 from a 300 μL sample. The efficacy of the released C14R against E. coli BL21(DE3) is illustrated. Overall, the multifunctionality of this approach presents a promising step towards on-demand wound care and thus for reducing side effects and antibiotic resistance