Chemnitz University of Technology

• Identifying the type and freshness level of beef where beef is primarily sold in packaged form. • Impedance spectroscopy enables non-invasive meat assessment, existing methods often rely on raw data or complex feature sets, failing to explain the rationale behind their selection or justify their complexity. • A systematic, physics-based feature engineering methodology that can classify muscle type and freshness in bovine meat simultaneously using a single neural network. • Feature selection is primarily based on significant parameter variation measured over a 14-day period, enabling a classification accuracy of up to 91,5% using both neural networks and SVM models. • The evolution of these parameters aligns with biological fundamentals, confirming the relevance of the selected features and underlying physical principles In this paper, we propose a systematic, physics-based feature engineering methodology that can classify muscle type and freshness in bovine meat simultaneously using a single neural network. We identify a minimal, yet highly informative set of features extracted from bioimpedance spectra based on observed spectral behavior and underlying physical principles. Feature selection in this study is primarily based on significant parameter variation measured over a 14-day period, particularly between days 2 or 3 and day 14 for a binary classification of meat in the two classes safe-to-sell and not-safe-to-sell. This variation serves as a strong indicator of sensitivity and contributes to achieving a high classification rate. The key features selected include parameters from the modified Fricke model and characteristic points in the α and β frequency bands (Rex, Rin, C, Im1, Im2 and Im3). We validate the stability of these features and assess the model’s interpretability. Our analysis highlights the consistent relevance of these parameters, enabling a classification accuracy of up to 91,5% using both neural networks and SVM models. The evolution of these parameters aligns with biological fundamentals, confirming the relevance of the selected features.

Abstract In this work, we consider a class of linear ill-posed problems with operators that map from the sequence space ℓ r ( r ⩾ 1 ) into a Banach space and in addition satisfy a conditional stability estimate in the scale of sequence spaces ℓ q , q ⩾ 0 . For the regularization of such problems in the presence of deterministic noise, we consider variational regularization with a penalty functional either of the form R p = ‖ ⋅ ‖ p p for some p > 0 or in form of the counting measure R 0 = ‖ ⋅ ‖ 0 . The latter case guarantees sparsity of the corresponding regularized solutions. In this framework, we present first stability and then convergence rates for suitable a priori parameter choices. The results cover the oversmoothing situation, where the desired solution does not belong to the domain of definition of the considered penalty functional. The analysis of the oversmoothing case utilizes auxiliary elements that are defined by means of hard thresholding. Such technique can also be used for post processing to guarantee sparsity. Some numerical illustrations are included.

Thermally sprayed self-fluxing NiCrBSi-based coatings modified with WC-Co as a reinforcing phase and h-BN as a solid lubricant were produced using conventional flame spraying and high-velocity oxygen-fuel (HVOF) spraying, followed by flame fusing to improve densification and interfacial bonding. The influence of the spraying energy input, coating composition, and post-deposition flame fusing on the microstructural evolution and tribological performance at room temperature (RT) and 400 °C are investigated. Novel insights into the stabilization and distribution of carbides (Cr 7 C 3 ), borides (CrB) and Ni-based intermetallic phases (Ni 3 B, Ni 31 Si 12 ), as well as the persistence, partial degradation, and anchoring behavior of h-BN particles are provided. Flame spraying leads to thicker coatings with splat-related inhomogeneities, whereas HVOF spraying produces thinner, denser coatings with finer microstructures. Flame fusing substantially modifies both coating series by eliminating splat boundaries, inducing partial remelting, and promoting the formation of eutectic structures and a dendrite-containing fusion zone that includes Mo 6 Ni 6 C. Fretting wear tests under severe reciprocating conditions at RT and 400 °C reveal a strong dependence of wear behavior on coating composition, microstructure, and processing history. Flame fusing the HVOF coatings induces a partial decomposition of WC and the formation of brittle W 2 CoB 2 , resulting in increased microcracking and higher wear rates of ~0.7–1.5 × 10 −4 mm 3 /Nm at RT. However, the wear rates at RT and 400 °C remain comparable due to embrittlement and the development of oxide-based tribolayers. Analyses of the worn surfaces indicate a temperature-dependent shift in the dominant wear mechanisms—from adhesive wear and surface fatigue at RT to mixed abrasive–adhesive wear combined with tribochemical oxidation at 400 °C, where oxidized tribolayers and plasticized splats facilitate lubrication and coefficient of friction (COF) stabilization. These findings provide new insights into the role of microstructural heterogeneities, WC decomposition, dendrite-containing fusion zones, and h-BN particle behavior in governing the tribological response of thermally sprayed coatings, outlining a pathway toward advanced coating solutions for high-performance valve components and related tribological applications. • h-BN and WC-Co particles exhibit distinct stability and interfacial bonding. • Flame fusing enhances densification and promotes metallurgical inter-splat bonding. • Partially degraded h-BN causes debris and reduces lubrication efficiency. • Flame fusing can form dendritic fusion zones and induces WC decomposition. • Process–structure design can improve wear resistance for high-temperature service.

Neuromorphic vision systems process continuous event streams and offer transformative potential for real-time applications. However, their evaluation remains tethered to methodologies from RGB imaging. These approaches convert asynchronous event streams into synchronized frames and ignore perception latency, creating a critical gap between benchmarks and real-world performance. To address this, we introduce the STream-based lAtency-awaRe Evaluation (STARE) framework. STARE integrates two core components: Continuous Sampling, maximizing model throughput to reduce the impact of latency, and Latency-Aware Evaluation, quantifying latency-induced online accuracy. To rigorously validate STARE, we developed ESOT500, a high-dynamic object tracking dataset with 500 Hz annotations. Experiments reveal that latency severely degrades online accuracy by over 50%. We further introduce two model enhancement strategies: Asynchronous Tracking, a fast-slow architecture that boosts model throughput, and Context-Aware Sampling, which dynamically adapts input to handle low event density cases. Overall, our work bridges the latency gap between models’ theoretical potential and real-world deployment.

Zusammenfassung Hintergrund Krebserkrankungen sind in Deutschland nach Herz-Kreislauf-Erkrankungen die zweithäufigste Todesursache. Infolge des demografischen Wandels nimmt die Bedeutung des Präventionsverhaltens diesbezüglich zu. Einerseits besteht ein breiter Konsens, dass die Krebsfrüherkennungsuntersuchung (KFU) ein sinnvolles Instrumentarium der Prävention bereitstellt, andererseits wird das bestehende Angebot an KFU nicht optimal nachgefragt. Ziel Es stellt sich die Frage, inwiefern Alter, Informationsverhalten, Geschlecht und das antizipierte subjektive Unbehagen (Empfindungsgrad) einer KFU das geplante Inanspruchnahmeverhalten beeinflussen und welche Aspekte bei der Weiterentwicklung von KFU zukünftig berücksichtigt werden sollten. Methoden/Ergebnisse Es wurden 216 Personen in Deutschland (Altersspanne 18–65 Jahre) über ein Access Panel per Zufall ausgewählt und online befragt (07/2023–09/2023). Zwischen Alter und geplantem Inanspruchnahmeverhalten besteht ein umgekehrt U‑förmiger Zusammenhang. Weiterhin konnte belegt werden, dass das Informationsverhalten positiv mit dem geplanten Inanspruchnahmeverhalten zusammenhängt. Die Interaktion mit Geschlecht und dem antizipierten subjektiven Unbehagen kann auf der Basis der Daten ebenfalls belegt werden. Demzufolge planen männliche Personen KFU eher in Anspruch zu nehmen, je weniger unangenehm diese eingeschätzt werden. Schlussfolgerung Die Forschungsergebnisse leisten einen Beitrag das Puzzel zu lösen, warum Frauen eher bereit sind als Männer, an einer KFU teilzunehmen und inwieweit geschlechtsspezifische Unterschiede in der Wahrnehmung von Krankheitsrisiken eine Rolle spielen.

To prevent hunting accidents, people in forests should be well-visible to others. However, there is debate which kind of protective clothing should be required. We created a database containing photographs of 22 individuals in forestial settings. The database is available online; for the present study a subset of images was used. The photographed persons (“models”) wore four different clothing variants adding to typical forest garment: Two conditions included protective clothing, either a reflective vest or a hat with reflective hatband. We included two conditions without protective clothing, either with a hat (without hatband) or with no hat, and a condition without person. For the present study, we cropped and scaled the image of the database to generate 800 stimuli (160 per condition). These were presented to N = 16 observers, who were asked to respond as quickly as possible without sacrificing accuracy whether a human was present. Reaction times (RTs) and miss rates depended on clothing. The two conditions without protective clothing had indistinguishable error rates, while fewer errors occurred with hatband, and even fewer with the vest. RTs were faster with protective clothing than without. In the absence of protective clothing, responses were faster without hat. Interestingly, vest and hatband led to indistinguishable RTs. However, individuals in vests were looked at earlier than individuals without. This difference between RTs and fixation latencies is likely explained by a frequent additional saccade from vest to face before the response, presumably to verify the human presence. In conclusion, although RTs suggest no advantage for wearing reflective vests over hatbands, error rates and eye-tracking data reveal a potentially critical safety benefit of wearing reflective vests in forestial environments. More generally, our study demonstrates the benefit of combining eye-tracking data with behavioral measures using a real-world example.

Abstract This study examines the effects of fiber content, distribution, and interfacial bonding on the thermal, mechanical, and tribological properties of copper matrix composites reinforced with short carbon fibers (C f ), produced via rapid sintering. Uniform composite feedstocks were prepared by mixing gas-atomized pure copper powder with 40 and 60 vol.% copper-coated short carbon fibers using a 3D mixer. The resulting blends were consolidated through the field-assisted sintering technique at temperatures between 900 and 940 °C. Microscopic analysis confirmed a random distribution of the fibers within the matrix and compatible interfacial bonding with the copper. Thermal tests with a dilatometer showed that increasing C f content significantly reduced thermal conductivity and the coefficient of thermal expansion. Tribological tests under low (6 N) and high (20 N) loads demonstrated significantly lower friction coefficients, the lowest 0.2, for the composites compared to pure copper. However, wear rates increased at 20 N under ball-on-disk conditions. This was in contrast to pure copper. The reduced tensile strength of the composites relative to pure copper was attributed to the diminished load-bearing capacity of the short fibers. Pure copper showed shallow localized corrosion pits. In contrast, composites—especially with 60 vol.% C f exhibited— corrosion initiating at the fiber–matrix interface. The lowest corrosion rate was observed at 25 °C.

Abstract Hydrofluoroethers (HFEs) are considered promising replacements for the high global warming potential (GWP) per- and polyfluoroalkyl substances (PFAS) in refrigeration, heat transfer, and electronic cooling applications. However, the scarcity and inconsistency of available thermophysical property data have hindered their reliable implementation and modeling. This study reports a comprehensive experimental investigation of HFE-7300 (1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane), including measurements of critical properties, density, vapor pressure, isobaric heat capacity, and speed of sound over wide temperature and pressure ranges. The experiments were complemented by ab initio calculations of ideal-gas thermodynamic properties, resulting in a consistent dataset suitable for model development. Correlations for vapor pressure, density, and heat capacities were derived and mutually validated for internal thermodynamic consistency. These results provide a robust foundation for developing a multiparameter equation of state for HFE-7300, while the performance of cubic, PC-SAFT, and LKP equations of state was also evaluated as an interim approach.