Kista Photonics Research Center

• Novel AFM steel resists liquid Pb penetration for over 1000 h at 650°C. • Liquid Pb corrosion resistance achieved despite high Ni content (12 wt.%). • Al-rich oxide scale formed at the lowest reported balanced Cr/Al composition. • B2-NiAl precipitates enable Al-reservoir effect at 650°C. • Martensitic microstructure accelerates Cr/Al diffusion for oxide scale growth. Two alumina-forming martensitic (AFM) steels containing less than 8 wt.% Cr were exposed for over 1000 h at 550°C and 650°C in static liquid Pb with controlled oxygen concentration to evaluate the formation of an alumina oxide scale and its protective capacity against corrosion. The AFM-1 steel (3.6 wt.% Al, 7.8 wt.% Cr) formed a continuous, protective oxide scale that effectively resisted Pb penetration under all conditions, particularly at 650°C, where performance improved due to the dissolution of B2-NiAl precipitates during prolonged exposure, releasing Al that migrated to the surface and enabled the formation of an Al-rich oxide layer, ensuring sustained protection and mitigating the localized nodular oxidation observed at 550 °C. In contrast, the AFM-2 steel (2.9 wt.% Al, 7.5 wt.% Cr) failed to develop a complete protective oxide layer, allowing molten Pb to penetrate and react with the substrate even at 650 °C, causing severe oxidation. These results demonstrate that, beyond a high Ni content (12 wt.%), achieving excellent corrosion resistance in liquid Pb requires a synergistic combination of an optimal Al/Cr balance, dissolution of B2-NiAl precipitates as an Al source, and enhanced atomic diffusion facilitated by the high density of subgrain boundaries in the martensitic microstructure.

The aim of this study was to explore if turn duration and the performance of step parameters during segments of the Timed Up and Go (TUG) test with and without cognitive dual-tasking (TUGdt) can discriminate between individuals with different cognitive ability. Participants were divided into groups (dementia = 57, mild cognitive impairment = 126, subjective cognitive impairment = 71, and controls = 50) and performed TUG and TUGdt (naming animals and reciting months in reverse order, respectively). Turn duration and forward and return walk (step parameters) were compared between adjacent groups for all conditions. Results were analyzed with logistic regression models, presented with standardized odds ratios, and generally showed longer turn duration during TUGdt for groups with lower levels of cognitive ability, whereas a small tendency was observed for step length/body height. While these results need to be confirmed, they may indicate the potential of assessing TUG segments, particularly turn duration, to identify risk of cognitive impairment.Trial registration numberNCT05893524.

We demonstrate 200 GBaud OOK, transmitter using a 1064 nm lithium niobate Mach-Zehnder modulator (MZM). We achieve performance below 6.25 % overhead HDFEC threshold and study different equalization configurations.

Abstract In contrast to traditional business models, digital business ecosystems (DBEs) have several distinctive features—heterogeneity of involved actors, symbiosis in the exchange of resources, co-evolution of their interactions, and self-organisation. Designing DBEs is a task demanding a well-defined DBE’s scope, roles and responsibilities of the actors, their interactions and dependencies, as well as versatile technologies and data. The study focuses on two DBEs—Marispace-X and Skippo in the maritime domain to capture the tenets of the blue economy with dataspaces. Because the design approaches to DBE are scarce due to the paradigm’s novelty, the study aims to evaluate a model-based design method, DBEmap. The evaluation results concerning practitioners’ perceived usefulness of the DBEmap and its support for integrating DBE-related perspectives and benchmarking DBE resilience are presented. Reflections on the applicability of DBEmap and its implications for organisational support, highlighting the systematic guidance and actionable outcomes observed in the two case workshops, are discussed alongside the study’s limitations and directions for future research.

Abstract. The Arctic Weather Satellite (AWS) is a project led by the European Space Agency (ESA) that has several novel aspects. From a technical perspective, it serves as a demonstrator of how to expand the network of operational satellite-based microwave sensors cost-effectively and acts as the proto-flight model for a suggested constellation of satellites, denoted as EUMETSAT Polar System (EPS) Sterna. The design philosophy has been to reduce complexity and instead focus the efforts on critical parts and characterise the instrument well before the launch. The single instrument onboard is a 19-channel microwave cross-track radiometer. There are 15 channels covering ranges around 54, 89 and 174 GHz. These are channels similar to ones found on existing sensors, however, thanks to the short development process, allowing use of more modern and recent technology, the performance and resolution of these channels on AWS exceed or match similar sensors, despite being a small satellite. Additionally, four channels around 325.15 GHz form a completely new frequency band for observations from space. The addition of these new channels aims to improve sensitivity to ice hydrometeors. In this article, we outline the mission and describe the instrument in detail, to support the usage of radiances measured by AWS. The satellite was launched in August 2024, and the status towards the end of the commissioning phase is reflected here. For example, a characterisation of the noise performance is provided, showing that the target specifications have been met, for most channels with a margin. This is except for two channels identified to have technical issues already before the launch. If EPS-Sterna is selected by EUMETSAT, these and other identified problems will be corrected, but otherwise the constellation is expected to consist of recurrent models of AWS with minor modifications.

The impact of pulsing a radio frequency (RF) glow discharge lamp on analytical aspects in glow discharge optical emission spectrometry (GD-OES) was investigated. The experiments were done with a LECO GDS950 spectrometer. This instrument has a fixed pulse frequency of 320 Hz and adjustable pulse duty cycles (PDC) 100%-6.4%. In the first part, emission yields (EY) were studied by measuring coated steel samples in compositional depth profiling (CDP) mode. Variations in EY were measured by integrating the intensity of emission lines from several elements through the entire coatings at several PDC settings. The results show generally small EY variations. For improved accuracy, a set of correction constants is suggested. In the second part, the impact on signal-to-background (S/B), signal-to-noise-noise (S/N), and precision was investigated using "high current" pulsing. This means increased pulse power leaving the average power constant at the different PDC settings. The samples were a low alloy steel and a high purity iron blank (background) sample. The results showed significant increase of the S/B and S/N for four out of six spectral lines investigated at increasing pulse power, showing potential for improved detection limits (DL). Furthermore, there was a tendency towards improved precision with higher pulse power. Finally, the effect on depth resolution in CDP was investigated by running a ZnNi coated steel using "high current" pulsing. It was found that the depth resolution was unaffected up to 30% PDC.

Abstract. The Arctic Weather Satellite (AWS) is a project led by the European Space Agency (ESA) that has several novel aspects. From a technical perspective, it serves as a demonstrator of how to expand the network of operational satellite-based microwave sensors cost-effectively and acts as the proto-flight model for a suggested constellation of satellites, denoted as EUMETSAT Polar System (EPS) Sterna. The design philosophy has been to reduce complexity and instead focus the efforts on critical parts and characterise the instrument well before the launch. The single instrument onboard is a 19-channel microwave cross-track radiometer. There are 15 channels covering ranges around 54, 89 and 174 GHz. These are channels similar to ones found on existing sensors, however, thanks to the short development process, allowing use of more modern and recent technology, the performance and resolution of these channels on AWS exceed or match similar sensors, despite being a small satellite. Additionally, four channels around 325.15 GHz form a completely new frequency band for observations from space. The addition of these new channels aims to improve sensitivity to ice hydrometeors. In this article, we outline the mission and describe the instrument to support the usage of radiances measured by AWS. The satellite was launched in August 2024, and the status towards the end of the commissioning phase is reflected here. For example, a characterisation of the noise performance is provided, showing that the target specifications have been met, for most channels with a margin. This is except for two channels identified to have technical issues already before the launch. If EPS-Sterna is selected by EUMETSAT, these and other identified problems will be corrected, but otherwise the constellation is expected to consist of recurrent models of AWS with minor modifications.

An experimental hot work tool steel with a leaner chemistry compared to the standard AISI-H13 grade, aimed at enhanced processability, was gas atomized and processed using laser powder bed fusion (L-PBF) to >99.8 % relative density. The lower carbon content (∼0.25 wt% vs. ∼0.4 wt% in H13) resulted in a softer as-built (AB), and quenched martensite (∼485 HV1 vs. 625 HV1 in H13), higher martensite-start temperature (∼360 °C vs. 280–320 °C), and about ∼18 % reduction in dilatation, ascribed to the volume expansive martensitic transformation. Charpy V-notch impact toughness in AB condition (>30 J) was higher than those reported for AB H13. These features account for the improved L-PBF processability. The tempering response in comparison with a wrought H13, was characterized by a larger precipitation of thermally stable Mo- and V-rich secondary hardening alloy carbides at the expense of the easy-to-coarsen Cr-rich ones, attributed to the higher Mo and lower Cr content in experimental alloy. The combination of lower C- and V-contents in experimental alloy, reduced the driving force for the precipitation of coarse vanadium rich carbides during austenitization, as confirmed by electron diffraction spectroscopy (EDS) and synchrotron X ray diffraction. This led to a stronger fine secondary hardening alloy carbide precipitation during tempering, and enhanced temper resistance. As elaborated by isochronal tempering, as well as tempering curves, reduction of the elements Si, and Cr shifted the secondary hardness peak to higher tempering temperatures. Consequently, tempering, and thermomechanical softening resistance was significantly enhanced in the new steel with a maximum hardness of ∼550 HV1 in over-tempered condition (i.e., slightly above secondary hardness peak). Thermal fatigue (TF) tests revealed a denser and finer TF crack network with a larger oxidation in experimental steel. Thereby, the TF crack penetration depth scaling with the local plastic yielding of the matrix was evidently shorter in the new steel compared with wrought H13, thanks to significantly improved hot hardness, thermal conductivity, and enhanced thermomechanical softening resistance. Finally, a proof of concept is demonstrated by processing a relatively large injection molding die (150 mm × 110 mm × 30 mm) with promising tensile and impact toughness properties after direct double tempering to 51 HRC, and 45 HRC hardness levels.