https://research.chalmers.se/ 2026-05-25 02:01:22 Visar de 30 senaste forskningspublikationerna för Chalmers https://research.chalmers.se//Images/chalmers_bldmrk.jpg Mitigating human-induced climate change requires large-scale deployment of renewable electricity technologies such as wind and solar power. However, the material supply chains underpinning these technologies pose environmental, climate, and social challenges and raise questions about the feasibility and equity of allocating available materials. In this context, the circular economy is increasingly explored as a means to address material demand and supply challenges and to support deployment at the scale and pace required to meet climate targets.This thesis develops a dynamic material flow analysis model combined with explorative scenario development to assess the effects of circular economy strategies on material demand and embodied emissions. Furthermore, it introduces a framework that integrates the model with the operationalization of selected equity principles to evaluate whether material supply requirements, and their reduction through circular economy strategies, align with equitable material allocation. The model is applied to wind and solar power deployment within Swedish and European Union decarbonization scenarios to 2050. Four circular economy strategies are considered: longer service lifespans, material intensity reduction, substitution, and recycling. Steel and concrete are included to assess circular economy effects on embodied emissions, and minor metals and rare earth elements to evaluate effects on material demand, supply, and equity.The results show that, while circular economy strategies reduce embodied emissions, transformative changes in steel and cement production remain necessary to achieve substantial reductions. For minor metals, material intensity reduction and substitution have the greatest potential to reduce total demand and associated supply requirements, with immediate effects that make them particularly relevant in the early and middle stages of the energy transition. In contrast, recycling and longer service lifetimes have more delayed effects. Results also vary across metals, with substantial differences in the compatibility of required supply with allocation based on equity principles. Overall, the effectiveness of circular economy strategies is time-, metal-, technology-, and market-share-dependent, indicating that no single strategy fits all contexts and that tailored portfolios are needed. A trade-off emerges within the transition period: strategies that most reduce gross metal demand can increase primary demand, requiring choices between minimizing total material throughput and reliance on primary supply. While the joint implementation of circular economy strategies reduces cumulative primary demand across metals by more than half and alleviates pressure on supply systems, high primary demand persists for most metals through 2050. For some metals, required supply exceeds allocation based on equity principles even under ambitious circular economy implementation.Overall, the findings show that circular economy strategies are necessary but not sufficient to eliminate primary extraction and achieve equitable material allocation. Complementary measures are required, which may include further material demand reductions, energy demand reduction, stronger governance, and a broader reconsideration of energy transition objectives. Doktorsavhandling 2026-05-23 23:54:42 https://research.chalmers.se/publication/552170 2026-05-23T23:54:42Z Comprehensive characterization of clouds and precipitation is fundamental to advancing our understanding of weather and climate systems. However, uncertainties persist in key quantities such as the mass of frozen hydrometeors and surface precipitation. Specialized spaceborne instruments provide high-quality measurements, but their orbital characteristics restrict their spatiotemporal sampling. Geostationary satellites, in contrast, offer continuous monitoring over continental scales, yet they have historically been underexploited. Relying solely on geostationary radiances, this thesis employs neural networks trained against gold-standard satellite products to retrieve frozen hydrometeor masses, cloud probabilities, and surface precipitation. Given the severely ill-posed nature of this inversion problem, the networks output case-specific probabilistic information targeting the irreducible uncertainty of these retrievals.The appended papers challenge traditional paradigms by demonstrating the value of infrared (IR) observations beyond cloud top properties. Results show that retrievals of frozen hydrometeor masses using only thermal IR channels closely align in performance with those incorporating all visible and IR channels. This alignment overcomes the daytime-only limitation of existing physics-based methods. Extending this approach, machine learning delivers skilful 2D and 3D retrievals of frozen hydrometeor masses and cloud probabilities from only a single IR channel. This capability enables creating the Chalmers Cloud Ice Climatology from multi-decadal records of globally harmonized geostationary observations. Parallel to cloud properties, a multispectral IR-based retrieval developed for Rain over Africa provides rainfall estimates that outperform established products in accuracy, resolution, and latency.These contributions unlock new applications for geostationary observations, providing unprecedented spatial and temporal continuity of hydrometeor data. The developed retrievals facilitate new insights into clouds, reduce observational uncertainties, and help validate climate models. Moreover, they carry clear societal value by allowing for timely estimates required for risk mitigation. Efforts to leverage these new capabilities are already underway. Doktorsavhandling 2026-05-23 13:06:59 https://research.chalmers.se/publication/552255 2026-05-23T13:06:59Z This paper presents a fully monolithically integrated compact asymmetrical Doherty power amplifier (DPA). The output combiner absorbs the intrinsic output capacitance Cout, of the devices with parallel inductors to resonate with Cout. Furthermore, output back-off (OBO) performance is improved by more than 8 dB thanks to asymmetric architecture, making the DPA suitable for handling high peak-to-average power ratio (PAPR) signals in 6G applications. The DPA implemented in novel Infineon 250 nm RF GaN on Si HEMT technology and was characterized under pulsed-RF measurement conditions, and demonstrates a maximum small signal gain of 9 dB at 7.2 GHz, an output power of 40 – 41.8 dBm at saturation, a saturation power added efficiency (PAE) of 20.9 - 32.7 % and a 8 dB back-off PAE of 15.5 - 26 % across a BW from 7 to 8 GHz, which is equal to 13.3 % fractional bandwidth (FBW), with a compact size of 4 mm × 4 mm, power density 1 W/mm2 Paper i proceeding 2026-05-23 12:02:24 https://research.chalmers.se/publication/551769 2026-05-23T12:02:24Z This paper presents a compact and fully monolithically integrated unbalanced Doherty power amplifier (DPA) for the FR3 mid-band spectrum, implemented in the WIN Semiconductors PQH1-0P 180 nm E-mode GaAs pHEMT technology. The design absorbs the intrinsic device output capacitance, Cout, using a parallel inductor in the Doherty combiner network to enhance bandwidth (BW). The asymmetric structure helps to improve output back-off (OBO) performance by more than 7 dB and makes it suitable for high peak to average power ratio (PAPR) signals. The DPA was evaluated under different auxiliary gate voltages to find the proper function as a gain enhancement technique in the saturation region to improve linearity. The DPA demonstrates a maximum small signal gain of 12.8 dB at 7.3 GHz, an output power of 23 - 24.5 dBm at saturation, a saturation drain efficiency (DE) of 45 - 57% and a 7 dB back-off DE of 30 - 45% over the BW from 7.3 to 8.7 GHz, which is equal to 17.5% fractional bandwidth (FBW), with a compact size of 2.5 mm × 2 mm. Paper i proceeding 2026-05-23 11:47:43 https://research.chalmers.se/publication/548933 2026-05-23T11:47:43Z The Onsala Space Observatory (OSO) operates multiple geodetic and geophysical instruments, including Very Long Baseline Interferometry (VLBI) radio telescopes, a superconducting gravimeter, Global Navigation Satellite System (GNSS) stations, tide gauges, water vapor radiometers (WVRs), a seismometer station, an aeronomy station, a time and frequency laboratory, and corner-cube reflectors for Interferometric Synthetic Aperture Radar (InSAR). Here, we report the updates of activities for the OSO geodetic facilities in 2022/2023. On the networking backbone, we added new dedicated 100 Gbps fibre lines between the on-site buildings in 2022, which allows the Onsala Twin Telescopes (OTT) to record at a sustained rate of 32 Gbps each. The necessary hardware for 100 Gbps connectivity to the outside world was installed in May 2024. Further highlights are the installation of a new ground-based microwave radiometer in May 2023 and the invar measurement systems on the OTT in December 2023. The new radiometer observes the sky brightness temperatures in 14 different frequency bands (between 22 to 31 GHz and 51 and 58 GHz). Övrigt konferensbidrag 2026-05-23 09:50:50 https://research.chalmers.se/publication/550040 2026-05-23T09:50:50Z In the most recent realization of the International Terrestrial Reference System, the ITRF2020, it was found that the VLBI scale parameter has a positive drift after 2013.75. While several possible reasons for this apparent VLBI scale drift are being discussed in the IVS community, a clear explanation for the issue has not been identified yet.In this study, we investigate reasons for the apparent VLBI scale drift in the ITRF2020 using the CATREF software, applying the same approach as used for the ITRF2020 production. We compare the models of discontinuities and post-seismic deformation used for VLBI station positions and velocities with those for co-located GNSS stations, and estimate the impact of these model differences on the VLBI scale drift.The analysis reveals that one of the main factors causing the scale drift can be non-linear behavior of the Ny-Ålesund station and Wettzell station. Övrigt konferensbidrag 2026-05-23 09:50:06 https://research.chalmers.se/publication/550045 2026-05-23T09:50:06Z In the new realisation of the International Terrestrial Reference System, ITRF2020, the VLBI scale factor time series shows a significant positive drift after 2013.75. During the past two years we investigated various causes for this scale drift and concluded that mis-modelling of the IVS station position temporal evolution, as well as ignoring major IVS station events, significantly impact the VLBI scale.This presentation focuses on the latter aspect: IVS station events, and is the result of an extensive study of possible station events that happened for the stations that observe, or observed, the most in the IVS network. We reviewed IVS annual reports and compiled a list of possible station events that could generate changes in the reference point positions of the VLBI telescopes.Five stations in the IVS network seem to be the most concerned: TSUKUB32, MATERA, ONSALA60, WETTZELL, and NYALES20. The five station events considered for MATERA correspond to repair of the concrete pedestal under rail in 2005 and azimuth rail wheel replacements in 2008, 2009, 2015 and 2018. There is one station event considered for WETTZELL due to gear wheels repair and new elevation bearings as well as re-adjustment of the dish surface in 2010, one station event for ONSALA60 due to subreflector control electronics replacement which triggered a need for a new pointing model in 2018, two station events for NYALES20 due to the replacement of the gear box in 2013 and a broken azimuth gear in 2016. We also consider two station events for TSUKUB32, due to the repair of the subreflector supporting structures in 2012 and the repair of the antenna base in 2013.To quantify the impact of these station events, we considered the official IVS combined solution, i.e. the IVS contribution to the ITRF2020 realisation, and our station event list, and calculated scale factors using the CATREF software with the single-technique combination strategy that was used to generate the ITRF2020.Including these station events as station breaks in the ITRF2020 discontinuity lists results in a reduction of 36~\% of the VLBI scale drift after 2013.75, even though some of these station events happened before 2013.75, and demonstrates the impact of a reference point position change on the VLBI scale. Övrigt konferensbidrag 2026-05-23 09:49:21 https://research.chalmers.se/publication/550043 2026-05-23T09:49:21Z We use the VGOS data from 2017 until the beginning of 2025 to estimate a Terrestrial Reference Frame (TRF) and a Celestial Reference Frame (CRF). These reference frames are then compared to ITRF2020 u2023 and ICRF3, as well as to a TRF/CRF solution calculated based on legacy S/X VLBI data up to the beginning of 2025. For the TRF, we find agreements on the level of a few millimeters for the VGOS stations with the longest observation spans. For the CRF, the differences are in general a few 100 µas. Övrigt konferensbidrag 2026-05-23 09:47:47 https://research.chalmers.se/publication/549982 2026-05-23T09:47:47Z Zuheir Altamimi officially introduced the ITRF2020-u2023 at the AGU24 conference in Washington DC on Monday, 9 December 2024. This marked the first update of ITRF2020, which showcases a novel approach to annual updates of the International Terrestrial Reference Frames (ITRF) without requiring global reprocessing from the four combination centers of space-geodetic technique that contribute to ITRF. The update integrates the original ITRF2020 combined solution, which includes data up to December 2020, with an additional three years of observations (January 2021 to December 2023) for the inter-technique combination. For VLBI specifically, the IVS Combination Center supplied the ITRS Center with three years of new data, derived from the combined contributions of 12 IVS Analysis Centers using seven different analysis packages. This involved the analysis of nearly 700 sessions. In particular, the three years of data were analyzed independently by the respective Analysis Centers, separate from the longer-term contribution to the ITRF2020, which spans 1979 to December 2021.Regarding the VLBI scale in the IVS contribution to ITRF2020-u2023, the scale drift exhibited distinct behavior over different periods. The drift from 2013.75 to 2021.00 differs significantly from the drift observed between 2021.00 and 2024.00. Although modeling the uplift of NYALES20 and accounting for station events improved the positive drift during the earlier period, it had no effect on the drift observed over the past three years. To understand these differences, the contribution of the IVS Combination Center to ITRF2020-u2023 was carefully compared with the initial contribution of ITRF2020. The primary objective of this study was to assess the strengths and limitations of this innovative approach to updating the ITRF, as well as to develop a strategy to update uniformly within all IVS Analysis Centers and the IVS Combination Center. Övrigt konferensbidrag 2026-05-23 09:46:30 https://research.chalmers.se/publication/550041 2026-05-23T09:46:30Z The International Terrestrial Reference Frame (ITRF) is realized by a global network of stations representing the four space geodetic techniques of VLBI, GNSS, SLR and DORIS. The technique-specific networks are combined using constraints such as local ties at colocation sites, and the assumption that station velocities and seasonal variations are identical for all techniques at a given site. Station motion is modeled primarily with linear trends to represent tectonic motion and glacial isostatic adjustment, complemented by post-seismic deformation models where necessary and applicable. Discontinuities are introduced to capture reference point changes associated with maintenance activities, including rail replacements at VLBI telescopes or equipment changes for GNSS and DORIS.The ITRF2020 revealed a systematic drift in the intrinsic VLBI scale, with the VLBI legacy S/X station in Ny-Ålesund contributing roughly 50% of the effect. The remaining causes are currently being investigated by an International VLBI Service for Geodesy and Astrometry (IVS) working group, whose mandate covers several potential contributors to the drift; one of its specific areas of focus concerns station- and network-level effects. Missing or unmodeled discontinuities in station time series have the potential to degrade both the accuracy and the long-term stability of the terrestrial reference frame.This study underscores the importance of detailed monitoring of VLBI instrumentation and demonstrates the impact of unmodeled equipment changes on scale accuracy. Using four VLBI legacy S/X stations (Tsukuba in Japan, Matera in Italy, Wettzell in Germany, and Zelenchukskaya in Russia) that underwent major repairs not represented in the ITRF2020 processing, we show that an additional 20% of the VLBI scale drift can be explained when these discontinuities are applied.These results highlight that achieving the Global Geodetic Observing System (GGOS) goals, 1 mm accuracy and 0.1 mm/yr stability for the terrestrial reference frame, requires precise documentation and modeling of instrument behavior during maintenance and repair activities. Paper i proceeding 2026-05-23 09:44:46 https://research.chalmers.se/publication/552254 2026-05-23T09:44:46Z In the recent realization of the International Terrestrial Reference System (ITRF2020), it was found that the VLBI scale parameter showed a positive drift after 2013.75. Although several possible reasons for this apparent VLBI scale drift are being discussed by the International VLBI Service for Geodesy and Astrometry community, a clear explanation for this issue has not yet been identified. In this study, we investigated the reasons for the apparent VLBI scale drift in the ITRF2020 using CATREF software, applying the same approach as that used for producing the ITRF2020. We estimated the impact of various models and methods used in the ITRF2020 on the VLBI scale drift, such as discontinuities applied to VLBI station positions and velocities, gravitational deformation models, and thermal deformation corrections. The analysis revealed that there is no simple explanation for the scale drift; however, the station position modeling of NYALES20 is one of the major contributors to it, and a combination of different deformation models and equipment changes for some stations can explain most of the drift observed in the scale parameter. Artikel i vetenskaplig tidskrift 2026-05-23 09:36:19 https://research.chalmers.se/publication/552253 2026-05-23T09:36:19Z Licentiatavhandling 2026-05-22 23:42:33 https://research.chalmers.se/publication/552230 2026-05-22T23:42:33Z Detection and characterization of biomolecules and biological nanoparticles at the single-molecule and single-particle level is important in fundamental biophysics and applied fields such as therapeutics and diagnostics. However, relying on ensemble methods for their characterization may obscure inherent heterogeneity, including subpopulations or conformations with distinct functional roles. There is also a need for analytical techniques that do not use fluorescent labels or physical tethers that might alter the physicochemical properties of the analyte. In response, label-free optical approaches for single-molecule and single-particle characterization are a growing field where direct characterization of particles in their native state is enabled.Within the field of label-free single-particle characterization, nanofluidic scattering microscopy (NSM) is a recently developed technique that combines dark-field microscopy with a nanofluidic platform to determine both size and molecular weight of diffusing particles. Detection is enabled by interference between light scattered by the particle and the nanochannel, yielding an optical contrast enabling characterization of proteins ranging from tens to hundreds of kilodaltons in molecular weight.While NSM has been demonstrated for the characterization of small biomolecules, extending the technique to larger and more complex nanoparticles introduces new challenges. In particular, non-specific adsorption to nanochannel walls has been a major obstacle to NSM characterization. In manuscript I, we overcome this obstacle by introducing a surface passivation strategy based on the formation of a polymer brush layer using the hydrophilic copolymer poly(l-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG). The protocol is effective for nanochannel cross-sectional dimensions down to 50 x 50 nm2 and reduces non-specific adsorption by several orders of magnitude. Furthermore, the passivation enables more accurate characterization of proteins and liposomes.Building on this improvement, manuscript II demonstrates how NSM can be applied to characterize biologically relevant nanoparticles. Specifically, we investigate twelve different lipid nanoparticle formulations and benchmark NSM against established techniques, such as nanoparticle tracking analysis and cryo-transmission electron microscopy, showing good agreement in inferred size distributions. Beyond size distributions, the optical contrast provides a second dimension of particle characterization, offering insights into particle composition and enabling comparison of formulations, as well as assessment of inter-sample heterogeneity. Licentiatavhandling 2026-05-22 20:59:30 https://research.chalmers.se/publication/552229 2026-05-22T20:59:30Z Social media has provided new opportunities for academics to disseminate their research results. They allow users to upload academic papers and links to published papers, track demand for their published articles, and engage in professional discussions with other users (Meishar-Tal and Efrat Pieterse, 2017). This paper aimed to study the use of academic and non-academic profiling sites and platforms amongst scholars at Chalmers University of Technology.We were also interested in the purpose that scholars had for using these platforms. Furthermore, using data about people who register in Mendeley as readers of papers, this article explored diverse types of users of scientific papers by scholars at Chalmers. These gave us insight into the different social media platforms being used, the purpose of use, the readers’ status and their topics of interest at Chalmers. Furthermore, this helped us to provide statistics on how scholarly publications at Chalmers are used for scientific, educational, or other professional purposes. Övrigt konferensbidrag 2026-05-22 17:21:41 https://research.chalmers.se/publication/516426 2026-05-22T17:21:41Z Electrical machines as the key components of EVs, provide the torque for the powertrain and determine the dynamic performance.Nevertheless, this is accompanied by torque ripple and the electromagnetic excitation of noise, vibration, and harshness (NVH).To minimize the torque ripple without hardware modification, the control-oriented approach is the focus in this study.This study starts from a design and analysis process, which establish the base of the analysis and mitigation of torque ripple.In this process, a reference permanent magnet synchronous machine (PMSM) is designed and its characteristics including efficiency map, torque, flux linkage, back-EMF, radial flux and force density, core loss, as well as reduced order model (ROM) are compared.Moving towards torque ripple mitigation, to develop the control-oriented approach, several designed-oriented approaches including skewing, notching and optimization are investigated first and set as the reference.To reduce manufacturing cost and increase flexibility, harmonic current injection method is investigated.To extract and inject harmonic components, the stochastic gradient descent algorithm and phase-locked loop are implemented to identify the amplitude and phase of the torque ripple, respectively.The results show that the control-oriented method can effectively reduce the torque ripple, and reveal the potential of this method, which is competitive with the design-oriented method but without hardware modification.To further analyze the torque ripple when the PMSM coupled with the inverter, a circuit-based PMSM model needs to be implemented. In this study, a time-efficient spatial harmonics modelling method of a PMSM in polar coordinates is proposed to reduce the flux mapping time. The results show a significant mapping time reduction utilizing the proposed method, and it captures the saturation and spatial harmonics while maintains high fidelity. Licentiatavhandling 2026-05-22 16:53:03 https://research.chalmers.se/publication/552227 2026-05-22T16:53:03Z Övrigt konferensbidrag 2026-05-22 16:13:27 https://research.chalmers.se/publication/505105 2026-05-22T16:13:27Z Architecture for Residential Care and Ageing Communities confronts urgent architectural design challenges within residential innovation, ageing communities and healthcare environments. The increasing and diversified demands on the housing market today call for alterability and adaptability in long term solutions for new integrated ways of residing. Meanwhile, an accentuated ageing society requires new residential ways of living, combining dignity, independence and appropriate care. Concurrently, profound changes in technical conditions for home healthcare require rethinking healing environments. This edited collection explores the dynamics between these integrated architectural and caring developments and intends to envision reconfigured environmental design patterns that can significantly enhance new forms of welfare and ultimately, an improved quality of life. This book identifies, presents, and articulates new qualities in designs, in caring processes, and healing atmospheres, thereby providing operational knowledge developed in close collaboration with academics, actors and stakeholders in architecture, design, and healthcare. This is an ideal read for those interested in health promotive situations of dwelling, ageing and caring Samlingsverk (redaktörskap) 2026-05-22 16:10:43 https://research.chalmers.se/publication/552228 2026-05-22T16:10:43Z We optimize the regenerator allocation in nonlinear elastic networks whose traffic demands have random data rates. Compared with previous regenerator allocation algorithms, our method achieves the same blocking probability with 11% fewer regenerator sites. Paper i proceeding 2026-05-22 16:03:36 https://research.chalmers.se/publication/876044e0-e969-439e-b1bc-c4320b17ea73 2026-05-22T16:03:36Z We investigate the use of 4D constant modulus modulation format combined with subcarrier modulation. Compared to the star-8QAM format, the proposed format has an improved performance gain from reducing the baud rate down to 1 GBd. Paper i proceeding 2026-05-22 15:56:11 https://research.chalmers.se/publication/e4368f1b-d3ae-4747-9fdd-f9ac6e7fbb19 2026-05-22T15:56:11Z Cross-correlations of VCSEL transverse mode groups with different apertures are used to predict dispersion dependent RIN. Experiments with wideband multimode fiber confirm the noise enhancement dependence on aperture, which increases with fewer mode VCSELs. Paper i proceeding 2026-05-22 15:37:11 https://research.chalmers.se/publication/f902d38a-cbb0-4e51-a969-e85b20280d8d 2026-05-22T15:37:11Z We investigate the effects of photon lifetime and damping of the modulation response on the quality of 50 Gbps 4-PAM signal generation with directly modulated 25G class VCSELs and identify the appropriate values for the K-factor. Paper i proceeding 2026-05-22 15:36:24 https://research.chalmers.se/publication/251040 2026-05-22T15:36:24Z The realization of 850 nm hybrid III-V/dielectric VCSELs is reported in order to realize low power consumption integrated light sources for SiN waveguide circuits, which find applications both in short-reach optical communication and optical sensors. Paper i proceeding 2026-05-22 15:30:23 https://research.chalmers.se/publication/249181 2026-05-22T15:30:23Z Using delayed self-heterodyne coherent detection, we characterized the FM noise across the C-band of a widely spaced microresonator-based frequency comb. The resulting linewidth depends on both the pump laser and the comb line position. Paper i proceeding 2026-05-22 15:29:38 https://research.chalmers.se/publication/250917 2026-05-22T15:29:38Z State conversion is a fundamental task in quantum information processing. Quantum resource theories allow for analyzing and bounding conversions that use restricted sets of operations. In the context of continuous-variable systems, state conversions restricted to Gaussian operations are crucial for both fundamental and practical reasons, particularly in state preparation and quantum computing with bosonic codes. However, previous analysis did not consider the relevant case of approximate state conversion. In this work, we introduce a framework for assessing approximate Gaussian state conversion by extending the stellar rank to the approximate stellar rank, which serves as an operational measure of non-Gaussianity. We derive bounds for Gaussian state conversion and distillation under approximate and probabilistic conditions, yielding new no-go results for non-Gaussian state preparation and enabling a reliable assessment of the performance of Gaussian conversion protocols. We also provide an open-source Python library to compute stellar-rank-related quantities and to assess Gaussian conversion. Artikel i vetenskaplig tidskrift 2026-05-22 15:26:55 https://research.chalmers.se/publication/552186 2026-05-22T15:26:55Z The Sun produces a steady signal of high-energy gamma rays through interactions of Galactic cosmic rays (GCRs) with its atmosphere. Observations with the Fermi Large Area Telescope and the High Altitude Water Cherenkov Observatory have revealed a gamma-ray flux significantly higher than early theoretical predictions, with unexpected temporal and spectral features that suggest a crucial role of the solar magnetic field. In this work, we model GCR-induced gamma-ray emission at the solar disk using the CRPropa framework, with realistic hadronic interactions, chromospheric density profiles, and several magnetic field configurations over the solar cycle. This allows us to quantify the gamma-ray emission of the entire solar disk for different phases of the solar activity cycle, and we present, for the first time, maps of the production locations of gamma rays on the solar surface. We consider both monoenergetic and realistic power-law injection spectra in a simplified dipole-quadrupole-current-sheet model and potential-field source-surface extrapolations for Carrington rotations during solar maximum and minimum. Our results show that magnetic mirroring and large-scale field topology strongly affect the spectral shape and spatial distribution of the emission, with slightly enhanced fluxes predicted at solar minimum. While our simulated baseline fluxes remain below observations, additional effects-such as heavier nuclei, Parker field mirroring, and deeper atmospheric interactions-could result in further enhancements of fluxes closer to observational values. Hadronic interactions not only produce gamma rays but also neutrinos. We estimate the expected neutrino flux from the Sun based on our predictions. We find that the expected flux is slightly below current upper limits from IceCube. Artikel i vetenskaplig tidskrift 2026-05-22 15:23:20 https://research.chalmers.se/publication/552187 2026-05-22T15:23:20Z Graphitic carbon nitride (g-C3N4) is a promising metal-free photocatalyst whose activity is often enhanced by nitrogen vacancies, though their microscopic role remains unclear. Using advanced ab initio calculations with large periodic supercells, we show that long-range buckling is essential to correctly evaluate defect energetics and thus determine the stability of distinct vacancy configurations. The most stable defects are found to introduce localized in-gap states corresponding to shallow acceptor and deep donor levels. These features explain (i) the experimental red-shifted absorption and (ii) suppressed photoluminescence observed in N-deficient g-C3N4 samples. Most importantly (iii) energy-level alignment at the water-semiconductor interface explains the enhanced photocatalytic reduction and reduced oxidation activity reported experimentally. Overall, our results provide a unified microscopic picture that quantitatively connects defect-induced electronic structure changes and experimental observables, offering a concrete predictive strategy for designing defect engineered carbon nitride and related metal-free photocatalysts. Artikel i vetenskaplig tidskrift 2026-05-22 15:12:44 https://research.chalmers.se/publication/552196 2026-05-22T15:12:44Z Massive stars regulate galaxy evolution and star formation through their physical and chemical feedback, but their formation remains poorly understood. Accretion-powered outflows provide important diagnostics of massive star formation. We present first results from the SOMA Atomic Outflow Survey, a far-infrared massive star formation survey using the FIFI-LS instrument on SOFIA. We report the detection of [O iii] 3P2 -> 3P1 emission at 52 mu m from the massive protostar G11.94-0.62, tracing highly ionized gas. We also detect [O i] 3P2 -> 3P1 and 3P1 -> 3P0 at 63 and 145 mu m tracing atomic gas, as well as CO J = 14 -> 13 at 186 mu m from highly excited molecular gas. The [O iii] and [O i] lines exhibit large line widths (similar to 200 and similar to 40-80 km s-1, respectively) and their morphologies are consistent with a wide-angle bipolar outflow. The properties of molecular tracers (12CO, 13CO, C18O, H2CO, and CH3OH) observed with the Atacama Large Millimeter/submillimeter Array support this interpretation. Ionized nebula and photodissociation region modeling imply an ionized outflow mass flux of similar to 8 & times; 10-5 M circle dot yr-1 and an atomic outflow mass flux of similar to 5 & times; 10-6 M circle dot yr-1, while the molecular outflow traced by CO has an implied mass flux of similar to 3 & times; 10-4 M circle dot yr-1. The mass and momentum flux in the ionized outflow are consistent with the primary disk wind, while the molecular component is mainly swept-up, secondary outflow gas. We also observe G11.94-0.62 with the Large Binocular Telescope in the near-infrared, potentially tracing the base of wide-angle outflow cavities. Spectral energy distribution modeling implies a protostellar mass m*=22.4-11+21M circle dot , while the [O iii] emission implies m* greater than or similar to 30 M circle dot and that the protostar is in the final stages of its accretion. Artikel i vetenskaplig tidskrift 2026-05-22 15:08:19 https://research.chalmers.se/publication/552197 2026-05-22T15:08:19Z Near infrared (near IR) absorbing Langmuir-Schaefer (LS) films based on a new n -octyloxy-substituted zinc(II) naphthalocyanine were prepared and successfully deposited onto a solid substrates. The supramolecular organization of floating layers and LS films was investigated by a combination of molecular modeling, surface pressure–area (π–A) isotherms, Brewster angle microscopy (BAM), atomic force microscopy (AFM), UV/Vis/near IR absorption spectroscopy, steady-state fluorescence and confocal fluorescence microscopy. Geometric molecular models based on the optimized structure of the n -octyloxy-substituted zinc(II) naphthalocyanine were used to estimate the molecular areas for face-on and edge-on packing and to rationalize the experimental isotherms. The naphthalocyanine forms continuous floating layers at the air/water interface with a small fraction of three-dimensional (3D) aggregates, as revealed by π–A isotherms and BAM. The supramolecular organization of these floating layers is largely preserved upon LS transfer: AFM shows thin films with an average thickness of about 2.7 nm, low roughness and a limited number of 3D aggregates, while UV/Vis/ near IR spectra of LS films with 1–20 layers display a linear increase of absorbance without significant band broadening. Confocal fluorescence microscopy demonstrates that thicker LS films retain a nearly homogeneous near IR fluorescence background with only a small population of brighter emissive domains. The combination of sterically hindered n -octyloxy substituents and controlled LS deposition thus affords low-defect, near IR absorbing and fluorescent naphthalocyanine films with tunable thickness. Such supramolecularly organized LS films are promising for applications in optoelectronics and sensing where controlled near IR optical response and morphological uniformity are required. Artikel i vetenskaplig tidskrift 2026-05-22 15:03:09 https://research.chalmers.se/publication/552206 2026-05-22T15:03:09Z We use a 10 nm frequency comb to transmit a 10 Tb/s 50x20 GBaud PM-64QAM superchannel over 80 km SMF. Using two unmodulated carriers we regenerate a phase locked receiver comb, enabling self-homodyne detection with record-low spectral overhead. Paper i proceeding 2026-05-22 13:33:51 https://research.chalmers.se/publication/250922 2026-05-22T13:33:51Z We propose and validate a discrete-time channel model for the temporal drift of the absolute polarization state and polarization-mode dispersion for coherent fiber optic systems. The model can be used in simulations to test and develop DSP for coherent receivers. Paper i proceeding 2026-05-22 13:28:45 https://research.chalmers.se/publication/248801 2026-05-22T13:28:45Z