@article{65585,
abstract = {{This article explores the relativity of Islamic normativity through the taṣwīb doctrine (kullu mujtahid muṣīb) as formulated by al-ʿAnbarī and received by al-Jāḥiẓ (d. 255/869), al-Jaṣṣāṣ (d. 370/981), and al-Baṣrī (d. 436/1044). Al-Jaṣṣāṣ reinterprets the thesis through the ḥanafī principle of ashbah bi-l-aṣl as a hermeneutical-methodological approach; al-Baṣrī elaborates it into an epistemo-logical model of normative plurality, while al-Jāḥiẓ articulates a soteriological theory of moral responsibility in the context of kalām. The analysis shows that classical Islamic legal theory developed a distinct modelof normativity that maintains binding force under conditions of pluralism and uncertainty. The article calls for renewed engagement with this tradition in contemporary debates on religious normativity and legal pluralism.}},
author = {{Abdelrahem, Mohammed}},
issn = {{2941-122X}},
journal = {{Forum Islamic-Theological Studies}},
keywords = {{IslamicTheology, Usul al-Fiqh, taswib, islamische Rechtsphilosophie, LegalTheory, Pluralism, OpenAccess}},
number = {{1}},
pages = {{94--111}},
publisher = {{LibreCat University}},
title = {{{Zur Relativität islamischer Normativität: Diskurslinien der taṣwīb-Lehre von al-Ǧāḥiẓ (gest. 869) zu al-Ǧaṣṣāṣ (gest. 981) und al-Baṣrī (gest. 1044) }}},
doi = {{10.71573/2941-122X_2026_5-1_154}},
volume = {{Vol. 5 (2026)}},
year = {{2026}},
}
@article{66036,
abstract = {{Light-assisted metal oxide-based chemiresistive gas sensors are widely explored for operation at relatively low temperatures, yet the investigation of the role of irradiance, as opposed to wavelength, remains underrepresented. Here, we systematically quantify the irradiance-dependent behavior of ordered mesoporous In2O3 under visible light illumination. Photoconductivity measurements reveal two distinct irradiance regimes consistent with trap-limited transport at low power and recombination- or saturation-limited transport at high power. Gas sensing experiments towards CO and H2 show a pronounced non-monotonic response, reaching maximum responses of 0.74 for 135 ppm CO at 67 mW cm−2 and 0.64 for 90 ppm H2 at 11 mW cm−2, followed by strong suppression at higher irradiance. Illumination also accelerated the response kinetics. At 60 ppm, t90 decreases from 96 to 12 s for CO and 141 to 27 s for H2, corresponding to an 8- and 5-fold faster response time, respectively. Near-ambient pressure-XPS under controlled atmosphere and density functional theory calculations indicate defect-mediated excitation. Oxygen vacancy states and illumination-induced modification of surface oxygen species govern this behavior. The results establish irradiance as a critical mechanistic parameter that determines whether In2O3 operates in a surface-controlled or bulk photoconductive regime. These findings highlight the need to explicitly optimize and report irradiance in illuminated gas sensor studies, and not only the power consumption of the light source.}},
author = {{Voth, Sven and Zhao, Zhenyu and Baier, Dominik and Glass, Alexandra and Elgabarty, Hossam and Sandberg, Oskar J. and Grundmeier, Guido and Tiemann, Michael and Smått, Jan-Henrik and Anttu, Nicklas and de los Arcos, Teresa and Weinberger, Christian}},
issn = {{2379-3694}},
journal = {{ACS Sensors}},
keywords = {{resistive gas sensing, indium oxide, photoactivation, irradiance, photoconductivity, charge carrier dynamics, oxygen vacancies}},
number = {{7}},
publisher = {{American Chemical Society (ACS)}},
title = {{{Role of Irradiance in Light-Activated In2O3Gas Sensors: Why More Light Is Not Always Better}}},
doi = {{10.1021/acssensors.6c01100}},
volume = {{11}},
year = {{2026}},
}
@article{63830,
abstract = {{ This study investigates the effect of dispersion gas (DG) flow on the formation and properties of maghemite (γ-Fe2O3) nanoparticles using standardized SpraySyn burners (SS1 and SS2). Several diagnostics were employed to characterize the spray and nanoparticles.
Increasing DG flow (6 - 12 slm) results in smaller droplet sizes (DS), cooler flame temperatures, shorter high-temperature droplet/particle residence times, and smaller agglomerates in the size range of 5 - 12 nm with narrower primary particle size distribution, corresponding to higher mass fractal dimensions, as supported by TEM and SMPS analysis, resulting in more compact agglomerates. BET and TEM confirmed decreasing primary particle sizes with increasing DG flow. Raman and XRD analyses predominantly identified maghemite, which shows a bimodal distribution of crystallite sizes, while SS1 samples have a greater proportion of larger crystallites.
The self-preserving size distributions of agglomerates with a geometric standard deviation of 1.5 are reached faster with increasing DG flow. The barrier effect of DG observed in SS1 leads to slower droplet combustion kinetics, higher temperatures, and delayed precursor release, which, along with downstream flow recirculation, result in significantly higher agglomeration rates outside the visible flame. SS2 demonstrates improved atomization, more stable flames, and finer, uniform nanoparticles with less carbonaceous residues (CR). Conversely, SS1 showed broader DS distributions and higher CR levels on the γ-Fe2O3 surface, especially at higher DG flow.
This work highlights the essential role of DG flow and nozzle geometry in controlling droplet evaporation, flame stability, and nanoparticle growth, offering insights for optimizing SFS and validating numerical models.
}},
author = {{Massopo, Orlando and Tischendorf, Ricardo and Gonchikzhapov, Munko and Kasper, Tina and Augustin, Peter and Özer, Burak and Reddemann, Manuel and Kneer, Reinhold and Sheikh, Mohammed-Ali and Mert, Aydan Akyildiz and Wiggers, Hartmut and Schmid, Hans-Joachim}},
issn = {{0032-5910}},
journal = {{Powder Technology}},
keywords = {{Spray flame synthesis, iron oxide nanoparticle, SpraySyn burner, Dispersion gas, Coaxial atomization, HiaT-SMPS}},
publisher = {{Elsevier BV}},
title = {{{Influence of dispersion gas flow on the spray characteristics and γ-Fe2O3 nanoparticles formation and properties in reference SpraySyn burners}}},
doi = {{10.1016/j.powtec.2025.121992}},
volume = {{470}},
year = {{2025}},
}
@article{55999,
abstract = {{Clean hydrogen is a key aspect of carbon neutrality, necessitating robust methods for monitoring hydrogen concentration in critical infrastructures like pipelines or power plants. While semiconducting metal oxides such as In2O3 can monitor gas concentrations down to the ppm range, they often exhibit cross-sensitivity to other gases like H2O. In this study, we investigated whether cyclic optical illumination of a gas-sensitive In2O3 layer creates identifiable changes in a gas sensor´s electronic resistance that can be linked to H2 and H2O concentrations via machine learning. We exposed nanostructured In2O3 with a large surface area of 95 m2 g-1 to H2 concentrations (0-800 ppm) and relative humidity (0-70%) under cyclic activation utilizing blue light. The sensors were tested for 20 classes of gas combinations. A support vector machine achieved classification rates up to 92.0%, with reliable reproducibility (88.2 ± 2.7%) across five individual sensors using 10-fold cross-validation. Our findings suggest that cyclic optical activation can be used as a tool to classify H2 and H2O concentrations.}},
author = {{Baier, Dominik and Krüger, Alexander and Wagner, Thorsten and Tiemann, Michael and Weinberger, Christian}},
issn = {{2227-9040}},
journal = {{Chemosensors}},
keywords = {{resistive gas sensor, chemiresistor, semiconductor, metal oxide, In2O3, mesoporous, hydrogen, humidtiy, machine learning, sustainable}},
number = {{9}},
pages = {{178}},
publisher = {{MDPI}},
title = {{{Gas Sensing with Nanoporous In2O3 under Cyclic Optical Activation: Machine Learning-Aided Classification of H2 and H2O}}},
doi = {{10.3390/chemosensors12090178}},
volume = {{12}},
year = {{2024}},
}
@misc{51136,
abstract = {{Iron oxide nanoparticles are very interesting for many applications in different industrial sectors. A promising
process to manufacture these nanoparticles is flame spray pyrolysis (FSP). A lack of understanding of the
individual sub-processes in FSP makes it challenging to tailor nanoparticle properties. This work provides
insights into the formation of iron oxide nanoparticles in a turbulent spray flame using Large Eddy Simulations
(LES), which are based on a comprehensive model, including customized submodels. Highlights are the
adaption of a turbulent combustion model and a bivariate hybrid method of moments for modeling nanoparticle
dynamics. The work focuses on the SpraySyn burner, which is a standardized laboratory burner and was
operated with a precursor-solvent mixture of ethanol and iron(III) nitrate nonahydrate. For studying the
relevance of precursor chemistry, LES using an evaporation-limited precursor chemistry model is compared
with a model that includes detailed iron chemistry. A further novelty is the inclusion of adsorption in the
simulation, which defines a third model for comparison. Sufficient validation is achieved for the undoped LES
using experimental data from the literature. A strong impact of the detailed iron chemistry and adsorption
is found on the precursor consumption and the aggregate and primary particle formation. Comparing the
particle diameters with experimental measurements from the literature and data generated for this work is
found unsuitable to asses the precursor chemistry model and revealed an urgent need for future experimental
and numerical research. This work serves as a step forward in realizing a reliable model.}},
booktitle = {{Applications in Energy and Combustion Science}},
editor = {{Fröde, Fabian and Grenga, Temistocle and Pitsch, Heinz and Dupont, Sophie and Kneer, Reinhold and Tischendorf, Ricardo and Massopo, Orlando and Schmid, Hans-Joachim}},
keywords = {{Flame spray pyrolysis, Iron oxide formation, Large eddy simulation, Method of moments, SpraySyn}},
publisher = {{Elsevier}},
title = {{{Large eddy simulation of iron oxide formation in a laboratory spray flame}}},
doi = {{https://doi.org/10.1016/j.jaecs.2023.100191}},
year = {{2023}},
}
@article{43441,
abstract = {{This paper reveals the 3D character of the intermetallic layer at the aluminum–steel interface which pops
up above the original sample surface during annealing. Popping out of the intermetallics was proven using
atomic force microscopy. The phase expands out of the plane due to the exothermic formation of the Al5Fe2
phase and the feasibility of surface diffusion. Milling by a focused ion beam enabled the comparison of the
chemical composition of the surface layer with the bulk interface, showing no difference. The growth direction
is both towards aluminum and steel — the main diffusion flux is from aluminum towards steel, and the new
intermetallic phase emerges at the steel side. The shortage of Al atoms causes a shift of the intermetallic as a
whole towards aluminum.}},
author = {{Šlapáková, Michaela and Kihoulou, Barbora and Veselý, Jozef and Minárik, Peter and Fekete, Klaudia and Knapek, Michal and Králík, Rostislav and Grydin, Olexandr and Stolbchenko, Mykhailo and Schaper, Mirko}},
issn = {{0042-207X}},
journal = {{Vacuum}},
keywords = {{Al-steel clad, twin-roll casting, 3D characterization, atomic force microscopy, diffusion direction, surface growth}},
publisher = {{Elsevier BV}},
title = {{{3D-structure of intermetallic interface layer in Al–steel clad material}}},
doi = {{10.1016/j.vacuum.2023.112043}},
volume = {{212}},
year = {{2023}},
}
@inproceedings{36335,
abstract = {{Transformation of Fe- and Cu-rich primary phase particles was studied in an Al-Li-based alloy prepared by twin-roll casting. Thin foils for combined STEM and SEM experiments were prepared by electrolytic twin-jet polishing. They were in-situ heated in a TEM heating stage and observed at 200 kV in the JEOL JEM 2200FS electron microscope equipped with STEM HAADF and BF detectors and SEM BSE and SE detectors working both in composition and topographic modes. The resulting structures were combined with EDS mapping performed directly in the heating holder. Dissolution and transformation of Cu- and Fe-rich particles occur above 500 °C. EDS maps acquired on the foil cooled down to room temperature show that Cu and Fe are both still present in newly formed particles, most likely indicating the presence of the Al7Cu2Fe phase.}},
author = {{CIESLAR, Miroslav and KŘIVSKÁ, Barbora and KRÁLÍK, Rostislav and BAJTOŠOVÁ, Lucia and Grydin, Olexandr and STOLBCHENKO, Mykhailo and Schaper, Mirko}},
booktitle = {{METAL 2022 Conference Proeedings}},
issn = {{2694-9296}},
keywords = {{Al-Li-based alloy, in-situ TEM, homogenization, phase transformation}},
location = {{Brno}},
publisher = {{TANGER Ltd.}},
title = {{{HOMOGENIZATION OF TWIN-ROLL CAST Al-Li-BASED ALLOY STUDIED BY IN-SITU ELECTRON MICROSCOPY}}},
doi = {{10.37904/metal.2022.4438}},
year = {{2022}},
}
@inproceedings{36339,
abstract = {{Al-Li-based alloys are an attractive material for aircraft and aerospace applications. Preparation of these alloys by twin-roll casting (TRC), which combines rapid metal solidification and subsequent plastic reduction in a single processing step, could improve the properties of the alloys compared to materials prepared by conventional direct-chill casting. A commonly used approach for identifying primary phases is a chemical analysis by energy dispersive spectroscopy (EDS). More accurate results can be achieved by combining the method with diffraction analysis. This process can be considerably simplified in microscopes equipped with automated crystal orientation and phase mapping (ACOM-TEM). Al-Cu-Li-Mg-Zr alloy was prepared by twin-roll casting. A combination of TEM and STEM images with chemical analysis by EDS and ACOM-TEM was used to obtain complex information about phases of boundary primary particles. The efficiency of the individual methods for the phase identification in TRC Al-Li-based alloys is discussed.}},
author = {{BAJTOŠOVÁ, Lucia and Grydin, Olexandr and STOLBCHENKO, Mykhailo and Schaper, Mirko and KŘIVSKÁ, Barbora and KRÁLÍK, Rostislav and ŠLAPÁKOVÁ, Michaela and CIESLAR, Miroslav}},
booktitle = {{METAL 2022 Conference Proeedings}},
issn = {{2694-9296}},
keywords = {{Al-Cu-Li-M-Zr-Fe alloy, twin-roll casting, phase identification, ACOM-TEM}},
location = {{Brno}},
publisher = {{TANGER Ltd.}},
title = {{{Phase identification in twin-roll cast Al-Li alloys}}},
doi = {{10.37904/metal.2022.4437}},
year = {{2022}},
}
@article{62813,
abstract = {{Nanostructured manganese oxides have a rich variety of morphologies and crystal phases which can undergo transformations during synthesis and application. Although these structural features are crucial for their performance, the mechanisms behind such transitions are not well understood. Herein, we describe the mechanism of transformation from layered 2D δ-MnO2 nanosheets to the scarcely reported γ-MnO2 nanocone morphology. Despite the common purpose of introducing Fe dopants to enhance the conductivity of layered manganese oxides, the Fe galvanic exchange reaction was found responsible for such coupled phase/morphology transition. Electrochemical characterization confirmed a distinct electrochemical behaviour of the nanocones, emphasizing the need to unravel the mechanism of 2D MnO2 transformation. Such mechanistic insights were gained by systematic and rigorous electron microscopy studies. The effect of the local chemical composition was determined by energy dispersive X-ray spectroscopy while electron energy loss spectroscopy unravelled the key influence of the oxidation state of Mn ions within nanosheets and nanocones. We propose and demonstrate a Mn2+-mediated oxidative mechanism of coupled morphology/phase transformation subjected to the equilibrium of Fe and Mn ions during galvanic exchange reaction. These findings contribute to the understanding of the growth and morphology/phase transformations of manganese oxide nanostructures, providing insights for the rational design of nanomaterials.}},
author = {{Aymerich-Armengol, Raquel and Cignoni, Paolo and Ebbinghaus, Petra and Linnemann, Julia and Rabe, Martin and Tschulik, Kristina and Scheu, Christina and Lim, Joohyun}},
issn = {{2050-7488}},
journal = {{Journal of Materials Chemistry A}},
keywords = {{manganese oxide, nanomaterials, TEM, supercapacitors}},
number = {{45}},
pages = {{24190--24198}},
publisher = {{Royal Society of Chemistry (RSC)}},
title = {{{Mechanism of coupled phase/morphology transformation of 2D manganese oxides through Fe galvanic exchange reaction}}},
doi = {{10.1039/d2ta06552e}},
volume = {{10}},
year = {{2022}},
}
@inproceedings{59220,
author = {{Schwabe, Tobias and Balke, Axel and Bezuidenhout, Petrone H. and Reker, Julia and Meyers, Thorsten and Joubert, Trudi-Heleen and Hilleringmann, Ulrich}},
booktitle = {{Fifth Conference on Sensors, MEMS, and Electro-Optic Systems}},
editor = {{du Plessis, Monuko}},
keywords = {{sensing, zinc oxide, thin-film transistor, oxygen measurement, low-cost electronics, water quality analysis, printable electronics, flexible electronics}},
pages = {{1104316}},
publisher = {{SPIE}},
title = {{{Oxygen detection with zinc oxide nanoparticle structures}}},
doi = {{10.1117/12.2501507}},
volume = {{11043}},
year = {{2019}},
}
@article{13187,
abstract = {{Abstract The reaction of Cu(I) bisguanidine complexes with nitric oxide and the formation of intermediate species were monitored via UV-vis spectroscopy at low temperature, with the occurrence of characteristic absorption bands. The origin of the emerging species and their character were substantiated by electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) studies showing a delocalized {CuNO}11 radical species. Furthermore, this system was transferred to the SuperFocus mixer setup, which allows rapid mixing and the determination of decay constants at ambient temperatures of the thermally sensitive species. However, these experiments demonstrated the limits of these systems, such as the NO saturation in organic solvents and a preferably precise temperature control within the SuperFocus mixer, which should be addressed in the future.}},
author = {{Oppermann, Alexander and Laurini, Larissa and Etscheidt, Fabian and Hollmann, Katharina and Strassl, Florian and Hoffmann, Alexander and Schurr, Daniela and Dittmeyer, Roland and Rinke, Günter and Herres-Pawlis, Sonja}},
journal = {{Chemical Engineering \& Technology}},
keywords = {{Copper guanidine complexes, Nitric oxide, SuperFocus mixer}},
number = {{8}},
pages = {{1475--1483}},
title = {{{Detection of Copper Bisguanidine NO Adducts by UV-vis Spectroscopy and a SuperFocus Mixer}}},
doi = {{10.1002/ceat.201600691}},
volume = {{40}},
year = {{2017}},
}
@article{63920,
abstract = {{Coordinatively unsaturated sites (CUS) present a key feature of alumina based catalysts as they are believed to act as Lewis-acid sites in heterogeneously catalyzed reactions. In the present study, the direct observation of active species on a fluoride-doped aluminum oxide catalyst is demonstrated. This new fluoride-doped aluminum oxide exhibits strong Lewis-acid sites and superior catalytic activity as compared to gamma-Al2O3. To emphasize the labile state of Lewis-acid sites, two distinctive states of the catalysts surface are addressed using H-1-Al-27 cross polarization (CP) MAS NMR. On the one hand, the highly dehydrated and active state after calcination at 700 degrees C and on the other hand the rehydrated and catalytically inactive surface (produced by contact to air) are probed. These experiments revealed the presence of significant amounts of coordinatively unsaturated sites in the form of 4-and 5-fold coordinated Al-sites on the highly dehydrated surface. In contrast to this, the rehydrated sample exhibited a severely restructured surface caused by the chemisorption of H2O which is ’constituted in a manner that was proposed in earlier models for gamma-Al2O3 surfaces.}},
author = {{Ahrem, L. and Scholz, G. and Gutmann, Torsten and Calvo, B. and Buntkowsky, G. and Kemnitz, E.}},
issn = {{1932-7447}},
journal = {{Journal of Physical Chemistry C}},
keywords = {{al-27 nmr, characterization, Chemistry, cross-polarization, dynamic nuclear-polarization, eta-alumina, gamma-alumina, hydroxy fluorides, ions, Materials Science, pentacoordinated al3+, Science & Technology - Other Topics, solid-state nmr, spectroscopic, structural insights}},
number = {{22}},
pages = {{12206–12213}},
title = {{{Direct Observation of Coordinatively Unsaturated Sites on the Surface of a Fluoride-Doped Alumina Catalyst}}},
doi = {{10.1021/acs.jpcc.7b02535}},
volume = {{121}},
year = {{2017}},
}
@inproceedings{9959,
abstract = {{Ultrasonic heavy wire bonding is a commonly used technology to conduct electrical devices in power electronics. In order to facilitate powerful solutions combined with an increased efficiency, involving a material change from aluminum to copper wire as conductor material takes place in recent years. Due to the material related properties, copper wire bonding requires significant higher bond processing parameters such as bond force and ultrasonic power compared to aluminum which can lead to damages or a failure of the bonded component. Therefore, a profound knowledge of the processes prevailing during wire bonding is essential to optimize the application of the copper wires and consequently to achieve the demands on quality and reliability. The behavior of different natural surface oxides of aluminum and copper are assumed to be one reason for the deviation in the required bond parameters. Accordingly, the impact of differently pre-treated substrates surfaces on which the bonding is applied were investigated in this study. First, all conditions investigated (as-received, oxidefree, AlOx and the CuOx) were characterized by utilizing scanning electron microscopy, energy dispersive X-ray spectroscopy, focused ion beam microscopy and atomic force microscopy. In addition, hardness tests were performed as well as perthometer measurements. Afterwards, a 500 $\mu$ m copper wire was bonded on the generated surfaces investigated. In consideration of the roughness, shear test of various bond times and microscopic images were evaluated. Finally, the results were compared and discussed. Overall, the current study indicates that an Al-oxide layer is beneficial for welding process in Cu wire bonding. On the contrary, the Cu-oxide is detrimental and leads to a delayed welding of the joining parts. Based on the obtained results, it can be expected that due to an ideal set of Al-oxide layers, lower optimal bond parameters can used to reach high bond strength with good reliability properties.}},
author = {{Eacock, Florian and Unger, Andreas and Eichwald, Paul and Grydin, Olexandr and Hengsbach, Florian and Althoff, Simon and Schaper, Mirko and Guth, Karsten}},
booktitle = {{IEEE 66th Electronic Components and Technology Conference}},
keywords = {{Ultrasonic copper wire bonding, Al-oxide, Cuoxide, oxide-free, roughness, morphology}},
pages = {{2111--2118}},
title = {{{Effect of different oxide layers on the ultrasonic copper wire bond process}}},
doi = {{10.1109/ECTC.2016.91}},
year = {{2016}},
}