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Benchmarks for diffuse interface modelling of fluid–solid interactions in a flow
No full textModels based on the coupling of phase-field methods with fluid dynamics are commonly used to simulate flow in complex geometries or in conjunction with phase transformation. Thereby, diffuse interfaces between fluid and solid are used, which requires the corresponding diffusive application of the boundary conditions with regard to the flow. While different approaches to achieving this are found in literature, a quantitative comparison of these methods is still missing. The present work aims to establish benchmarks addressing the diffuse fluid–solid transition for interfaces with and without wall velocity. Furthermore, different models from literature are revisited and comparatively discussed in detail. Using the defined benchmark cases, a quantitative assessment of these models is performed to investigate their accuracy for varying interface widths and different phase-field profiles. The results show that the best choice of the diffuse model is problem-dependent
Electron-Donating Ligand in Oxidorhenium(V) Chemistry: Consequences for Isomerism and Catalyst Properties
No full textThe bidentate, monoanionic dimethyloxazoline-phenol ligand HL1 was used to synthesize the corresponding oxidorhenium(V) complex [ReOCl(L1)] (2). Ligand HL1 is equipped with two electron-donating tert-butyl substituents. The HdmozR class of ligands has so far enabled the stereoselective synthesis of the so-called N,N-trans isomers of oxidorhenium(V) complexes. In contrast, when precursor complex [ReOCl(OPPh)(SMe)] (P1) and HL1 are reacted, in addition to the expected N,N-trans isomer (trans-2), also the N,N-cis isomer (cis-2) is formed. So far, this isomerism has only been observed for the nonmethylated phenol-oxazoline ligand Hoz, resulting in mixtures of complexes N,N-cis/trans [ReOCl(oz)] (cis/trans-1). For trans-2, the catalytic properties in oxyanion (perchlorate and nitrate) reduction were studied. Due to the slow kinetics in the latter, the two cationic complexes [ReO(L1)]X (X = SOCF_3̅, 3a; X = OCCF_3̅, 3b) were synthesized. Cationic triflate complex 3a showed the highest conversion rates in perchlorate reduction compared to 3b and chlorido complex trans-2, corresponding to the weakness of the coordinating anion. A targeted synthesis of the dioxidorhenium(VI) complex [ReO(L1)] (4), the product of nitrite (NO_2̅) reduction, allowed for mechanistic and electrochemical investigations. The solid-state structures of complexes cis-2, trans-2, 3b, and 4 were characterized by single-crystal X-ray diffraction
Version 8 IMK/IAA MIPAS measurements of ClO
No full textGlobal distributions of chlorine monoxide (ClO) were retrieved from infrared limb emission spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), covering the time period from July 2002 to April 2012. The retrieval was performed by constrained non-linear least squares fitting using spectral lines in the fundamental band of ClO around 844 cm−1. The vertical resolution of V8 ClO is 4 km at 18–20 km and 7.5–9.5 km at 40 km altitude. The considerable improvement at 40 km with respect to the previous V5 data version is achieved by extension of the spectral range for retrieval of upper stratospheric ClO. Errors are by far dominated by measurement noise and increase from 0.4–0.5 ppbv at 20 km to 0.8 ppbv at 50 km altitude. Thus, in general, individual ClO profiles are noisy, and profile averaging has to be performed for, e.g., analysis of the upper stratospheric maximum. However, strongly enhanced lower stratospheric ClO amounts of more than 1.5 ppbv during polar winter are well detected in single measurements. Along with the standard representation of the data, an alternative coarse grid representation that obviates the need to apply averaging kernels in certain situations is also provided. Due to improved modeling of the atmospheric continuum and the instrumental offset, the high bias in upper stratospheric ClO that had particularly affected the previous V5 data over the period 2005–2012 has been removed. A comparison with ClO measurements of the Microwave Limb Sounder (MLS) on the Aura satellite shows good agreement between the lower stratospheric enhancements observed by the two instruments in polar winter. There is also good agreement between the upper stratospheric ClO amounts observed in the northern hemisphere and at southern hemispheric low latitudes. With the support of simulations from the Earth system model ECHAM/MESSy Atmospheric Chemistry (EMAC), deviations between the ClO amounts of MIPAS and MLS in the Antarctic lower stratosphere during July and in the upper stratosphere, especially at southern mid- and high latitudes during winter, are attributed to the different local solar times of the measurements
Multispectral X-ray Spectroscopy of Actinide Compounds
No full textUnderstanding the electronic structure and chemical bonding properties of the actinide (An) elements poses a great challenge [1-13]. The core-to-core and valence band resonant inelastic X-ray scattering (CC/VB-RIXS) and high energy resolution X-ray absorption near edge structure (HR-XANES) techniques measured at the An M4,5 and L2,3 absorption edges or ligand K edges probe the occupied and unoccupied parts of the valence band of the actinide elements with extraordinary energy resolution and in combination with computational quantum chemistry detailed information on the chemical bonding can be obtained [1-13].
Examples of oxidation states studies of systems containing actinides in metalorganic compounds [1,6,11], geochemical systems [5], nanoparticles [9] and spent nuclear fuel will be discussed. In addition, multi-absorption edges, multi-techniques approaches will be discussed from the actinide and ligand perspective for probing the bonding properties and more specifically the bond covalency of the actinide-ligand chemical bond [4,12,13].
[1] T. Vitova, et al., Phys. Rev. B 82 (2010) 235118.
[2] T. Vitova, et al., Inorg. Chem. 54 (2015) 174.
[3] S. Bahl, et al., Inorg. Chem. 56 (2017) 13982–13990.
[4] T. Vitova, et al., Nat. Commun. 8 (2017) 16053.
[5] I. Pidchenko, et al., Environ. Sci. Technol. 51 (2017) 2217.
[6] T. Vitova, et al., Chem. Commun. 54 (2018) 12824.
[7] T. Vitova, et al., Inorg. Chem. 57 (2018) 1735.
[8] M. Zegke, et al., Chem. Sci. 10 (2019) 9740.
[9] G. Kauric, et al., Mater. Today Adv. 8 (2020) 100105.
[10] T. Vitova, et al., Inorg. Chem. 59 (2020) 8–22.
[11] T. Vitova, et al., Chem. Sci. 13 (2022) 11038–11047.
[12] B. Schacherl, et al., Nat. Commun. 16 (2025) 1221.
[13] A. R. Bajaj, et al., Inorg. Chem. 64 (2025) 12297–12312
Functional Test Generation for In-Field Testing of Deep Learning Models with Test Storage Constraints
No full textEmbodied GHG emissions of buildings – The hidden challenge for effective climate change mitigation – Supplementary materials
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Exploring The Role of Technology for Accessible Stadium Experiences for People With Limited Mobility
No full textOrbital Ordering in the Charge Density Wave Phases of BaNi(AsP)
No full textWe use resonant x-ray scattering at the nickel L edges to investigate the interplay between orbital degrees of freedom and charge density waves (CDWs) in the superconductor BaNi(AsP). Both the incommensurate and commensurate CDWs in this system exhibit strong resonant enhancement with distinct energy and polarization dependencies, indicative of orbital ordering. Azimuthal-angle-dependent measurements reveal a lowering of the local Ni site symmetry, consistent with monoclinic or lower point group symmetry. The scattering signatures of both CDWs are dominated by contributions from Ni d orbitals, with similar orbital character despite their distinct wave vectors. These findings point to a shared orbital-driven formation mechanism and provide new insight into the symmetry breaking and orbital and nematic fluctuations in the high-temperature regime of the superconductor BaNi(AsP)
Inkjet printed tunable BST/P(VDF-TrFE) dielectrics on polymeric substrates for varactor applications
No full textFerroelectric materials are highly promising for dielectric properties in the field of flexible printed electronics as varactors due to their non-linear behavior. For the utilization in flexible films, composite inks consisting of ceramics and polymers are of great interest with BST/P(VDF-TrFE) being one of the promising choices. Herein, we are developing printable inks and studying the influence of ferroelectric ceramics (BST) and ferroelectric polymers (P(VDF-TrFE)) as well as non-ferroelectric ceramics (Al2O3) and non-ferroelectric polymers (PMMA). We were able to fabricate fully inkjet-printed BST/P(VDF-TrFE), BST/PMMA and Al2O3/P(VDF-TrFE) varactors with dielectric layer thicknesses between 1.24 and 1.70 μm. Dielectric investigations show that BST/P(VDF-TrFE) greatly outperforms the other systems and reaches a maximum tunability of 12.80% @40 V with a high Q factor of 27.7