Between sustainability commitments and anticipated market requirements: Exploring the resilience of the techno-economic innovation paradigm in the midstream of construction research

This article studies ways of dealing with the tension between a commitment to sustainable and responsible research and anticipated market requirements in the midstream of a research process in architecture and construction. Using a slightly modified version of Socio-Technical Integration Research (STIR), we explored the chances of questioning the primacy of the techno-economic innovation paradigm by deliberately provoking reflections through STIR interactions. Our research underlines the difficulties and limitations of challenging an orientation towards values of efficiency and productivity in favour of social and environmental values in the midstream of the research process and examines how the techno-economic innovation paradigm is able to insulate itself against critical questioning. It sheds light at the critical role of the underlying assumption that marketability of prospective outcomes is not one objective amongst others but the precondition for all others and at two argumentative patterns we termed the "lack-of-agency" and the "reconciliation-after-all" pattern

Closing the yellow gap with Eu- and Tb-doped GaN: one luminescent host resulting in three colours

Gallium nitride (GaN) is a key material when it comes to light-emitting diodes (LEDs) and has pushed the LED revolution in lighting and displays. The concept of down-conversion of a GaN-based blue LED offers the possibility to provide efficient generation of monochromatic, high-color purity light resulting in a highly efficient warm-white all-nitride phosphor-converted light emitting diode (pc-LED). Although the down conversion of blue light from InGaN LEDs has become a dominant technique for producing white light, there are still some technical challenges, e.g. the immiscibility of GaN and InN and the lattice mismatch between the substrate and InGaN, that have to be overcome. Here we demonstrate the doping of bulk GaN with europium, terbium and the combination of both resulting in intriguing luminescence properties, pushing the role of GaN:Eu,Tb as a chief component in future light emitting diodes. This colour tuning proves that one luminescence host can provide three colours (red, green and orange) and that even the so called “yellow gap” could be closed with a III-nitride. By using one material for all colours, it will be possible to overcome the technical challenges in building up LED devices, which will open up new capabilities for modern highly efficient phosphors

¹⁴N, ¹³C, and ¹¹⁹Sn solid-state NMR characterization of tin(II) carbodiimide Sn(NCN)

We report the first magic-angle spinning (MAS) nuclear magnetic resonance (NMR) study on Sn(NCN). In this compound the spatially elongated (NCN)$^{2-}$ ion is assumed to develop two distinct forms: either cyanamide (N≡C–N$^{2-}$) or carbodiimide ($^{-}$N=C=N$^{-}$). Our $^{14}$N MAS NMR results reveal that in Sn(NCN) the (NCN) $^{2-}$ groups exist exclusively in the form of symmetric carbodiimide ions with two equivalent nitrogen sites, which is in agreement with the X-ray diffraction data. The $^{14}$N quadrupolar coupling constant ∣∣C$_{Q}$∣∣ ≈ 1.1 MHz for the $^{-}$N=C=N$^{-}$ ion in Sn(NCN) is low when compared to those observed in molecular compounds that comprise cyano-type N≡C– moieties ( ∣∣C$_{Q}$∣∣ > 3.5 MHz). This together with the information from $^{14}$N and $^{13}$C chemical shifts indicates that solid-state NMR is a powerful tool for providing atomic-level insights into anion species present in these compounds. The experimental NMR results are corroborated by high-level calculations with quantum chemistry methods

Eu- and Tb-adsorbed Si3_{3}N4_{4} and Ge3_{3}N4_{4}: tuning the colours with one luminescent host

Phosphor-converted white light emitting diodes (pc-LEDs) are efficient light sources for applications in lighting and electronic devices. Nitrides, with their wide-ranging applicability due to their intriguing structural diversity, and their auspicious chemical and physical properties, represent an essential component in industrial and materials applications. Here, we present the successful adsorption of Eu and Tb at the grain boundaries of bulk β-Si$_{3}$N$_{4}$ and β-Ge$_{3}$N$_{4}$ by a successful combustion synthesis. The adsorption of europium and terbium, and the synergic combination of both, resulted in intriguing luminescence properties of all compounds (red, green, orange and yellow). In particular, the fact that one host can deliver different colours renders Eu,Tb-β-M$_{3}$N$_{4}$ (M = Si, Ge) a prospective chief component for future light emitting diodes (LEDs). For the elucidation of the electronic properties and structure of β-Si$_{3}$N$_{4}$ and β-Ge$_{3}$N$_{4}$, Mott–Schottky (MS) measurements and density functional theory (DFT) computations were conducted for the bare and RE adsorbed samples

SnCN₂: A Carbodiimide with an Innovative Approach for Energy Storage Systems and Phosphors in Modern LED Technology

The carbodiimide SnCN$_{2}$ was prepared at low temperatures (400 °C–550 °C) by using a patented urea precursor route. The crystal structure of SnCN$_{2}$ was determined from single‐crystal data in space group C2/c (no. 15) with a=9.1547(5), b=5.0209(3), c=6.0903(3) Å, β=117.672(3), V=247.92 Å$^{3}$ and Z=4. As carbodiimide compounds display remarkably high thermal and chemical resistivity, SnCN$_{2}$ has been doped with Eu and Tb to test it for its application in future phosphor‐converted LEDs. This doping of SnCN$_{2}$ proved that a color tuning of the carbodiimide host with different activator ions and the combination of the latter ones is possible. Additionally, as the search for novel high‐performing electrode materials is essential for current battery technologies, this carbodiimide has been investigated concerning its use in lithium‐ion batteries. To further elucidate its application possibilities in materials science, several characterization steps and physical measurements (XRD, in situ XANES, Sn Mössbauer spectroscopy, thermal expansion, IR spectroscopy, Mott‐Schottky analysis) were carried out. The electronic structure of the n‐type semiconductor SnCN$_{2}$ has been probed using X‐ray absorption spectroscopy and density functional theory (DFT) computations

Fördernde und hemmende Faktoren beim Aufbau von Wertschöpfungsketten für Körnererbsen und Ackerbohnen

Um den Einsatz von Ackerbohnen und Körnererbsen sowohl in der Tier- als auch in der Humanernährung zu fördern und zu optimieren, wurden kritische Erfolgsfaktoren erarbeitet, die sich positiv oder negativ auf die Etablierung von Wertschöpfungsketten vom Anbau über Verarbeitung bis hin zur Vermarktung auswirken