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Dinuclear Copper(I) Complexes Featuring Metal-Metal Interactions and a μ₂-Bridging Phosphane With Additional Olefinic Binding Sites
Item type: Journal Article
Li, Zhongshu; Himmelbauer, Daniel; Oswald, Jan; et al. (2026)
The molecule Ptrop₃ contains in each trop unit (trop = dibenzo[a,d]cyclohepten-5-yl) a rigid central seven-membered ring with an olefinic binding site making Ptrop3 potentially a tetradentate ligand. Nevertheless, in mononuclear CuI complexes, [Cu(Ptrop₃)X] [X = Cl (2), OTf (3), BF₄ (4')], this phosphane behaves mainly as a highly bulky ligand (cone angle approx. 250 °) and the interactions between Cu¹ center and the C═Ctrop units are remarkably weak, such as in other related Cu trop-type complexes. The reaction of [Cu(Ptrop₃)(OTf)] with Cu⁺ sources allows the preparation of dinuclear complexes [Cu₂(μ₂-Ptrop₃)(μ₂-X)]⁺ (X = Cl, OTf, TFA), which contain a μ₂-bridging P center and in which the interaction between the Cu¹₂ core and the olefins is significantly enhanced. Experimental investigations and DFT calculations indicate that the uptake of a Cu⁺ ion by the mononuclear complex [Cu(Ptrop₃)(OTf)] (3) is a kinetically and thermodynamically favorable process.
Probing ferroic states in oxide thin films using optical second harmonic generation
Item type: Review Article
Nordlander, Johanna; De Luca, Gabriele; Strkalj, Nives; et al. (2018)
Forthcoming low-energy consumption oxide electronics rely on the deterministic control of ferroelectric and multiferroic domain states at the nanoscale. In this review, we address the recent progress in the field of investigation of ferroic order in thin films and heterostructures, with a focus on non-invasive optical second harmonic generation (SHG). For more than 50 years, SHG has served as an established technique for probing ferroic order in bulk materials. Here, we will survey the specific new aspects introduced to SHG investigation of ferroelectrics and multiferroics by working with thin film structures. We show how SHG can probe complex ferroic domain patterns non-invasively and even if the lateral domain size is below the optical resolution limit or buried beneath an otherwise impenetrable cap layer. We emphasize the potential of SHG to distinguish contributions from individual (multi-) ferroic films or interfaces buried in a device or multilayer architecture. Special attention is given to monitoring switching events in buried ferroic domain- and domain-wall distributions by SHG, thus opening new avenues towards the determination of the domain dynamics. Another aspect studied by SHG is the role of strain. We will finally show that by integrating SHG into the ongoing thin film deposition process, we can monitor the emergence of ferroic order and properties in situ, while they emerge during growth. Our review closes with an outlook, emphasizing the present underrepresentation of ferroic switching dynamics in the study of ferroic oxide heterostructures.
Regolith-Rich PEEK Composite Bricks: Steps Towards Space-Ready Lunar Construction Materials
Item type: Journal Article
Torre, Roberto; Ferro, Carlo Giovanni; Bono, Lorenzo; et al. (2025)
This study introduces a novel composite construction material composed of lunar regolith combined with PEEK in dry powder form. The work demonstrates significant advantages over alternative methods, primarily by reducing production power consumption and simplifying the manufacturing process. Building on previous research that explored binder optimization through process simplification and targeting predefined shapes, this work delves deeper into a comparative analysis of high-performance thermoplastics. Among the various options, PEEK demonstrates the most favorable properties. The study investigates key processing parameters and evaluates the effects of vacuum processing and temperature testing on mechanical properties. The research also evaluates the effects of vacuum processing and temperature testing to assess the material’s performance under lunar conditions. Comparative analysis is performed with standard performance of various reinforced and unreinforced concretes and with standard requirements for construction bricks as per ASTM standards. This shows that the composite, with an organic binder content as low as 5 wt%, has great potential. Notably, the improvements achieved through vacuum curing ensure compliance with lunar environmental conditions and alignment with most Earth-based engineering standards. Samples compacted at 7.50 MPa with 10 wt% binder, and tested at room temperature, achieve a compression strength of 16.3 MPa, exceeding that of industrial floor bricks and matching that of building bricks used on Earth. Bending strength (7.4 MPa) aligns with steel fiber-reinforced and high-strength concretes. Vacuum curing further enhances these properties, with an observed increase of +66% in bending strength and +33% in compression strength.
Determination of Heat Transfer Coefficient in a Film Boiling Phase of an Immersion Quenching Process
Item type: Journal Article
Cukrov, Alen; Sato, Yohei; Landek, Darko; et al. (2025)
The numerical solution of flow and temperature fields in and around a hot metal component being immersed into a cooling fluid offers powerful insights into investigating industrial quenching processes. The calculation requires a simultaneous solution of the Navier Stokes and the according energy equation. Difficulties arise at the boundaries where high heat transfer rates are forced from the solid surface to the fluid due to high metal temperatures. Heat transfer rates are determined based on the similarity theory, but reliable heat transfer equations valid for the high temperature typical of quenching processes are rare. This paper presents a two-fluid VOF (volume-of-fluid method) approach, giving an insight into the transient heat transfer and its oscillations. Unlike our previous publications, this paper uses the lumped heat conduction model to obtain the heat transfer coefficient in the film boiling heat transfer mode. Its application leads to an estimation of an average heat transfer coefficient. Furthermore, the unsteady distribution of the heat transfer coefficient values, shown in our previous paper, is now supplemented with the corresponding flow behavior obtained using the numerical simulation. In our approach, the vapor bubble formation during the film boiling phase is tracked directly (DNS of interface motion, not turbulence), and the unsteady heat transfer coefficient distribution is obeyed.
We Are Not Equipped to Identify the First Signs of Cyber–Physical Attacks: Emotional Reactions to Cybersecurity Breaches on Domestic Internet of Things Devices
Item type: Journal Article
Budimir, Sanja; Fontaine, Johnny R.J.; Huijts, Nicole M.A.; et al. (2024)
The increasing number of domestic Internet of Things (IoT) devices in our lives leads to numerous benefits, but also comes with an increased risk of cybersecurity breaches. These breaches have psychological consequences for the users. We examined the nature of the psychological impact of cybersecurity breaches on domestic IoT by investigating emotional experiences in a scenario study (Study 1) and a field experiment (Study 2) using the five emotion components of the Component Process Model (CPM) and emotion regulation as a framework. We replicated a three-dimensional structure for emotional experiences found in a previous study, with an addition of an ancillary fourth dimension in the second study. The first dimension represents emotional intensity. The second bipolar dimension describes constructive vs. unconstructive action tendencies. On the third dimension, also bipolar, cognitive and motivational emotion features are opposed to affective emotion features. The fourth dimension, labeled distress symptoms, mainly reflects negative emotions. In Study 2, most of the introduced frequent irregularities on IoT devices were not noticed, and the intensity of emotional reactions and tendencies to react in a constructive way decreased throughout the phases of the experiment. These findings reveal that we are not emotionally equipped to identify potential threats in the cyber world.