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Do Investors Trust in AI Investments of European Companies?
No full textAnnouncements of emerging technologies often lead to notable stock market reactions, with Artificial Intelligence standing out due to its transformative potential and growing regulatory attention. Yet, most research on investor responses to AI disclosures focuses on U.S. firms, leaving the distinct European context unexplored.
Using a short-term event study of 526 AI-related announcements by STOXX Europe 600 firms between 2015 and 2024, we report a significantly negative average stock return of -0.176% within a three-day window. However, announcements detailing specific AI technologies, involving collaborations with AI specialists, or made after the release of ChatGPT are associated with less negative reactions. In contrast, references to EU regulatory frameworks like the AI Act show no significant effect. Our findings confirm generally negative investor reactions to AI announcements but show that in Europe, strategic factors such as announcement specificity, collaborations, and timing also significantly mitigate these effects
Strong quartic anharmonicity and thermoelectric performance in antiperovskite Sr3XN (X = P, As, Sb, and Bi)
No full textAntiperovskite (APV) materials have garnered significant attention due to their diverse physical properties. The self-consistent phonon (SCP) theory and the Boltzmann transport equation (BTE) were combined to calculate thermal and electronic transport properties of APV Sr3XN (X = P, As, Sb, Bi) based on density functional theory (DFT). Pronounced quartic anharmonicity was identified in Sr3PN and Sr3AsN, attributed to the vibrations of Sr atoms. This distinctive characteristic induces four-phonon (4ph) scattering, significantly reducing the lattice thermal conductivity (κL), particularly at elevated temperatures such as 900 K, with values as low as 0.58 W·m−1·K−1 for Sr3PN. Additionally, Sr3BiN exhibits remarkable electrical conductivity and a high Seebeck coefficient, leading to a promising figure of merit (ZT) of up to 1.03, underscoring its potential as a thermoelectric material. These findings demonstrate that the ultra-low lattice thermal conductivity driven by 4ph scattering, coupled with excellent thermoelectric properties, makes these materials promising candidates for high-efficiency thermoelectric applications
AMPK-mediated HCN4 channel phosphorylation contributes to age-related intrinsic bradycardia
No full textThe regulation of the hyperpolarization-activated cyclic nucleotide–gated 4 (HCN4) channels in pacemaker myocytes is essential for maintaining physiological cardiac rhythm. HCN4 dysfunctional behavior is among the major factors contributing to sinus node disease, a primary cause of pacemaker implantation. Previous work has shown that AMP-activated protein kinase (AMPK) activation leads to sinus bradycardia, a process attributable to cardiac remodeling that involves a decrease in HCN4 membrane expression, but the mechanism underlying this event remains unclear. We show here that AMPK can act as a posttranslational effector by phosphorylating Ser1157 at the C terminus of HCN4, a modification associated with a decrease in HCN4 membrane expression contributing to altered electrophysiological properties of cardiac pacemaker cells. Furthermore, we provide evidence that AMPK is constitutively activated in aged, but not young, mice, correlating with an increased development of intrinsic bradycardia. These findings support the view that AMPK is a key player in cardiac rhythm regulation and provide new insights into the molecular mechanisms underlying age-related changes in cardiac rhythm regulation
Acceptor-doping of lead-free (Ba0.82Ca0.18)(Zr0.08Ti0.92)O3 with Fe induces piezoelectric hardening
No full textThe growing need for electroactive components in modern electronics, autonomous vehicles, and miniaturized medical equipment requires new sustainable materials with improved piezoelectric performance. The lead-free perovskite system (Ba,Ca)(Zr,Ti)O3 has already been demonstrated to be an excellent alternative to Pb(Zr,Ti)O3 for soft-type piezoelectric applications, but its adaptability to hard-type piezoelectric requirements remains unclear. Here, we demonstrate hardening of (Ba,Ca)(Zr,Ti)O3 via targeted defect formation using Fe-acceptor doping. We reveal the underlying defect equations and provide experimental evidence for the formation of defect complexes using electron paramagnetic resonance. We describe the influence of Fe-doping on the crystal structure, phase transition behavior, and electromechanical properties, and found outstanding electrostrictive coefficients, up to 0.063 m2 C−4, in highly doped relaxor-like (Ba,Ca)(Zr,Ti)O3. Aging experiments on poled compositions with <1 Fe revealed that piezoelectric hardening through defect complexes occurs in BCZT only after prolonged aging. This resulted in an increase of the figure of merit for resonance applications by over 280 and considerably improved high-power behavior, exceeding the stability of commercial Pb(Zr,Ti)O3 materials. Our results demonstrate the large potential of (Ba,Ca)(Zr,Ti)O3 for resonant piezoelectric applications and simultaneously give insights into the defect chemistry of acceptor-doped (Ba,Ca)(Zr,Ti)O3
Automating Spaghetti Diagrams: a machine vision-based approach with privacy by design
No full textRoute diagrams, known as Spaghetti Diagrams, are easy-to-use yet powerful tools for improving production layouts. They visualize worker routes or material flow to identify and reduce non-value-added movement activities. Traditionally, these diagrams are created manually, a process that is both time-consuming and prone to subjectivity. This limits the scalability and consistency of the method. The presented solution utilizes a machine vision-based tracking approach to create Spaghetti Diagrams more efficiently and objectively. Through partially automated analysis and novel visualization possibilities, the digitalization of Spaghetti Diagrams encourages data-driven decision-making and accelerates the prioritization of potential issues within manufacturing processes. The method integrates privacy by design principles into data collection and processing, ensuring compliance with data protection standards, which is an essential factor for industrial use. These integrated measures not only address previous limitations but also facilitate straightforward adoption of the method in industrial environments, demonstrated by implementation in a learning factory
Requirement analysis and approach for Chaos Engineering in industrial production
No full textChaos Engineering, a proven methodology in software development, enhances system resilience by deliberately inducing controlled incidents to expose and address vulnerabilities. While established in IT, its application in industrial production remains limited despite similar resilience demands. This paper explores its suitability for industrial contexts, identifying implementation requirements via a systematic literature review. A formalized requirements definition is presented, forming the basis for a structured process model. The process model is demonstrated conceptually and evaluated against existing risk management approaches, highlighting its unique contributions and practical advantages for improving resilience in industrial production environments
Innovative Freight Wagons in Single Wagon Load Transport: Potentials and Impacts on Improvement of Competitiveness
No full textSolid-state formation reactions of Ba0.82Ca0.18Zr0.08Ti0.92O3 piezoceramics
No full textThe lead-free piezoceramic (Ba,Ca)(Zr,Ti)O3 system has been a focus of scientific research due to its outstanding electromechanical properties, rivaling those of conventional lead-based materials. However, poor reproducibility and unwanted secondary phases are major obstacles to the further development of these materials. Here, we used thermal analysis and high-temperature in-situ X-ray diffraction to identify the chemical reactions taking place during the solid-state synthesis of Ba0.82Ca0.18Zr0.08Ti0.92O3. We identified the phase formation sequence, discovered novel and formerly unknown intermediate phases, and defined the conditions for secondary phase formation. Strategies for the removal of the main secondary phases, namely CaTiO3 and a polytitanate phase, were proposed. This resulted in an increase of the small-signal piezoelectric coefficient d33 by 28 %. The reaction sequence generated in this study will help to improve the processing conditions for this material system to allow for controlled microstructure engineering and enhanced electromechanical properties
Self-Driven Fluid Imbibition of Salt Solutions into Mesoporous Films
No full textFluid water imbibition into nanoscale porous materials is important in nature and technology and has
been shown to follow Lucas-Washburn behavior. Looking at drop imbibition into nanoscale porous films the
imbibition reaches a steady state governed by capillary imbibition and evaporation which is reflected in a constant
imbibition length. This imbibition length in a steady state depends on the porous structure as well as on the
material’s wettability and the fluid evaporation rate, for example. As the presence of salts affects these
parameters, the imbibition length is expected to be influenced by the solutes present in the drop. Here, we show
the influence of salt presence, salt concentration, and ion type on the fluid imbibition of an aqueous salt solution
into mesoporous silica films. We observe, that salts affect the Lucas-Washburn imbibition occurring directly after
drop positioning on mesoporous films. Interestingly, the presence of salts also causes a continuous increase of
the characteristic imbibition length at longer time scales preventing the formation of a steady state after the initial
Lucas-Washburn-like imbibition. We identified a self-amplified fluid pumping mechanism using mesoporous silica
films. We attribute this continuous fluid pumping and thus the continuous increase of the imbibition length to the
increasing osmotic pressure within mesoporous materials upon constant fluid flow and fluid evaporation.
Understanding aqueous salt solution imbibition into mesoporous films is an important aspect e.g. in the context
of material exchange between drops through mesoporous films
