https://research.chalmers.se/ 2026-07-26 03:37:07 Visar de 30 senaste forskningspublikationerna för Chalmers https://research.chalmers.se//Images/chalmers_bldmrk.jpg X's Community Notes is a crowdsourced fact-checking system. To improve its scalability, X recently introduced "Request Community Note" feature, enabling users to solicit fact-checks from contributors on specific posts. Yet, its implications for the system -- what gets checked, by whom, and with what quality -- remain unclear. Using 98,685 requested posts and their associated notes, we evaluate how requests shape the Community Notes system. We find that contributors prioritize posts with higher misleadingness and from authors with greater misinformation exposure, but neglect political content emphasized by requestors. Selection also diverges along partisan lines: contributors more often annotate posts from Republicans, while requestors surface more from Democrats. Although only 12% of posts receive request-fostered notes from top contributors, these notes are rated as more helpful and less polarized than others, partly reflecting top contributors' selective fact-checking of misleading posts. Our findings highlight both the limitations and promise of requests for scaling high-quality community-based fact-checking. Paper i proceeding 2026-07-24 10:19:39 https://research.chalmers.se/publication/9902b2f7-8c3f-4d74-9f67-5cc5b39d2ad6 2026-07-24T10:19:39Z This synthesis lecture presents the current state-of-the-art in applying low-latency, lossless hardware compression algorithms to cache, memory, and the memory/cache link. There are many non-trivial challenges that must be addressed to make data compression work well in this context. First, since compressed data must be decompressed before it can be accessed, decompression latency ends up on the critical memory access path. This imposes a significant constraint on the choice of compression algorithms. Second, while conventional memory systems store fixed-size entities like data types, cache blocks, and memory pages, these entities will suddenly vary in size in a memory system that employs compression. Dealing with variable size entities in a memory system using compression has a significant impact on the way caches are organized and how to manage the resources in main memory. We systematically discuss solutions in the open literature to these problems. Chapter 2 provides the foundations of data compression by first introducing the fundamental concept of value locality. We then introduce a taxonomy of compression algorithms and show how previously proposed algorithms fit within that logical framework. Chapter 3 discusses the different ways that cache memory systems can employ compression, focusing on the trade-offs between latency, capacity, and complexity of alternative ways to compact compressed cache blocks. Chapter 4 discusses issues in applying data compression to main memory and Chapter 5 covers techniques for compressing data on the cache-to-memory links. This book should help a skilled memory system designer understand the fundamental challenges in applying compression to the memory hierarchy and introduce him/her to the state-of-the-art techniques in addressing them. Bok 2026-07-24 10:05:11 https://research.chalmers.se/publication/229914 2026-07-24T10:05:11Z This book offers an introduction to quantum technology that is specifically tailored to economists, students of economics, and professionals in the financial and payments industries. The book reviews quantum speedups that have been identified for algorithms used to solve and estimate economic models, including function approximation, linear systems analysis, graphical modeling, Monte Carlo simulation, matrix inversion, principal component analysis, linear regression, dynamic programming, interpolation, numerical differentiation, and true random number generation. It also provides an overview of quantum financial technology and its potential applications in economics and finance. Written by an interdisciplinary team with backgrounds in economics, computer science, and physics, this book offers a valuable guide for researchers and practitioners who want to understand the implications and possibilities of quantum technology for the field of economics. Bok 2026-07-24 10:04:25 https://research.chalmers.se/publication/540692 2026-07-24T10:04:25Z Thermal de-icing and snow melting systems heat surfaces to prevent snow and ice buildup. They provide benefits compared to conventional winter maintenance methods such as salting and plowing, including improved safety, reduced environmental impact, and automated operation. Hydronic Heated Pavement Systems (HHPS) achieve this by circulating heated fluid through embedded pipes. These systems enhance sustainability by using shallow geothermal energy and storing solar heat collected during summer for use in winter. HHPS can provide a reliable, renewable alternative to energy intensive electrical resistance heating, particularly in critical infrastructure areas that require continuous operation. This paper presents findings from the International Energy Agency (IEA-TCP) Task 38, which focused on advancing ground source de-icing and snow-melting systems. Drawing from over 50 documented cases across several countries, the study highlights technical, operational, and design considerations for HHPS. It examines both thermal performance and mechanical integration, identifying key design parameters such as pipe configuration, embedment depth, and material compatibility. It also explores how these parameters influence energy efficiency and snow melting performance. The results show that HHPS can significantly reduce winter energy demand and environmental impact, particularly when integrated with solar harvesting and seasonal thermal storage. However, challenges remain related to thermal performance under varying climatic conditions, long-term mechanical durability, and system scalability. To support broader adoption, the paper suggests practical design strategies. These include energy zoning, i.e., dividing pavements into independently controlled heating sections, and optimized integration with low-carbon energy sources, aimed at enabling more sustainable and resilient infrastructure in cold climates. Paper i proceeding 2026-07-24 08:36:57 https://research.chalmers.se/publication/549791 2026-07-24T08:36:57Z The present paper reports on the investigation of long-range LH2 aircraft concepts for year 2050 entry into service. The paper attempts to identify the limitations set by the LH2 storage technology when targeting typical design payload-range missions. In particular, the paper aims at providing a reasonable estimate of the upper efficiency levels set by low-weight rigid cell foam insulated tank technology, when integrated in a conventionallyshaped airframe. Additionally, a sensitivity study on the gravimetric efficiency of the tanks will be carried out, to identify the required roadmap for LH2 storage technology that is compliant with the typical long range mission requirements. Results for the different LH2 aircraft are compared with a year 2020 and year 2050 reference aircraft fueled with conventional jet-A. Paper i proceeding 2026-07-24 08:29:50 https://research.chalmers.se/publication/532872 2026-07-24T08:29:50Z This article presents a new method to help achieving the rapid response of tire virtual optimization–predicting the camber-sideslip combined mechanical characteristics based on pure camber and pure sideslip. First, the influence mechanism of camber on sideslip is explored. Using the method of combining test and simulation, a finite element (FE) model of 235/55R18 tire is established, and the influence law of camber on sideslip is summarized. Secondly, the prediction method is studied. The linear region prediction is based on the load transferring along tire width caused by camber. The transition zone mechanical characteristics is predicted by treating camber as a function of load and the friction prediction considers local carcass camber (LLC) function. Finally, the application verifications of the prediction method in Magic Formula (MF) and UniTire are carried out. The prediction results are compared with the Similarity result and the MF identification result. Paper i proceeding 2026-07-24 08:25:20 https://research.chalmers.se/publication/537173 2026-07-24T08:25:20Z A key challenge in developing terahertz Schottky-barrier diode-based receivers operating at ambient temperatures is to overcome the complexities of fabrication and machining, and to achieve efficient coupling between the waveguide feed horn and the THz signal. This paper presents characterization of WM-57, In0.22Ga0.78As Schottky-barrier diode mixers realized on a 2-μm-thick indium phosphide membrane. The mixers were pumped by a quantum-cascade laser operating at 3.4 THz; the radio and local-oscillator signals were spatially superimposed using a Mylar beam splitter and coupled to the mixers via an integrated pyramidal horn antenna. A double-sideband receiver noise temperature of 28 500 K was measured at 3.4 THz for 6-μm Mylar at an IF of 1.5 GHz, with 2-mW of LO power coupled to the mixer. The DSB receiver noise temperature corrected for atmospheric attenuation is 27 600 K. These results represent a key step toward room-temperature THz front-end systems for limb-sounding instruments to detect trace gases in the mesosphere and lower thermosphere of the Earth's atmosphere. Artikel i vetenskaplig tidskrift 2026-07-24 08:08:15 https://research.chalmers.se/publication/d040b99c-278c-42c3-9c4b-0e5b2131fe01 2026-07-24T08:08:15Z Energy studies as a field is, due to its strong grounding in engineering and economics, overall dominated by reductive ideas around the role of people in energy systems. In particular, the diversity and agency of local level energy users is commonly overlooked and poorly understood, with consequences for energy transition policy and practice. This conceptual review brings together critiques of simplistic and idealised portrayals of energy users, who they are and what roles they are thought to play in energy system transformation. It forefronts studies that pay explicit attention to power relationships and injustice through a critical theory lens, in particular feminists, intersectional, decolonial and indigenous power theories. The review deconstructs the concept of energy user and contrasts such dominant ideas with alternative perspectives. It employs framing as analytical tool for sense-making and reflection around the power relationships that have shaped how global energy systems function and the role of the users in reshaping, resisting and reframing these systems. The conceptual analysis illustrates the myriad ways in which energy users can be framed and shows why these representations matter for knowledge-making, practice and policy aiming at low-carbon transitions. We identify current knowledge gaps and future research frontiers in proposing framings and user-oriented interventions which embrace rather than smooth over the heterogeneity, messiness and politics of user roles in energy systems and transitions. Reviewartikel 2026-07-23 16:26:15 https://research.chalmers.se/publication/553072 2026-07-23T16:26:15Z Reinvestments in wastewater pipe networks pose financial challenges due to high costs in combination with the complexity of rehabilitation prioritisation. Lack of pipe data and unknown pipe conditions are some factors contributing to the complexity. In Sweden, many of the wastewater pipe networks were constructed in the 1960s and 1970s and are now approaching the end of their technical life. With large investments anticipated in the coming decades, water utilities have the potential to reduce costs by identifying and prioritising high-risk wastewater pipes for rehabilitation. In this study, a risk-based decision model is presented to facilitate the strategic rehabilitation of wastewater pipe networks. The model is based on a two-tiered approach: the first tier identifies high-priority pipes for Closed-Circuit Television (CCTV) inspections, while the second tier utilises the CCTV-inspection results to estimate the probability of failure and update the risk assessment. A multi-criteria decision analysis model was utilised to prioritise wastewater pipe rehabilitation as well as CCTV-re-inspections. Hence, the model represents a novel integration of local CCTV-grades when establishing re-inspection frequencies and prioritisation of wastewater pipe rehabilitation prioritisation. Within six months, the model was implemented in the wastewater pipe network in Kungsbacka municipality, Sweden. The model enabled the development of an inspection plan and rehabilitation prioritisation, representing a significant step towards cost-effective and efficient wastewater pipe network management. Artikel i vetenskaplig tidskrift 2026-07-23 16:22:11 https://research.chalmers.se/publication/553074 2026-07-23T16:22:11Z This study investigates how academics in precarious transition develop and adapt academic networks to support writing for publication amid institutional instability and geographic mobility. Drawing on longitudinal data from three displaced scholars, including interviews, feedback interactions, and repeated Academic Network Plots, we analyze changes in network size, structure, and function. Across cases, network development is explained by three integrated moves: (1) targeted initiation with selective pruning: purposeful outreach aligned with publishing aims while de-prioritizing less productive ties; (2) value brokering with role repositioning through reciprocal collaborations; and (3) durability orientation via structuring follow-ups and outputs (co-authorships, revision cycles, grants) to stabilize ties despite mobility. These moves function as counterstrategies to the epistemic marginalization described in centre-periphery research, showing how scholars under precarious conditions reshape their trajectories despite structural hierarchies. We extend research on academic networking by showing how precarity shapes both access to networks and scholars' positions within them. We offer a transition-sensitive framework that integrates structural and functional change with temporality, brokerage, and mobility. Implications are outlined for mentoring design, institutional support, and equitable participation in global knowledge production. Artikel i vetenskaplig tidskrift 2026-07-23 16:20:20 https://research.chalmers.se/publication/553078 2026-07-23T16:20:20Z Membrane action can substantially enhance the resistance and deformation capacity of restrained reinforced concrete (RC) elements, offering critical additional capacity for elements subjected to impulsive loading. However, its practical utilization remains limited, largely due to the absence of a consistent, simplified approach capable of describing the full structural response. This study conducted experimental investigation of membrane action in six longitudinally and rotationally restrained RC beams subjected to static three-point bending. The specimens varied in slenderness, reinforcement ratio, and fracture strain of the reinforcement. All beams exhibited combined flexural and membrane action, with an enhanced peak resistance attributable to compressive membrane action (CMA). Clear differences in reinforcement fracture and cracking development were observed in the post-peak response across the specimens, reflecting the influence of geometry, reinforcement properties and boundary conditions. The results showed that CMA contributed significantly to the energy absorption capacity of specimens with lower slenderness or lower reinforcement ratios, while more slender beams with reinforcement with higher fracture strain benefited primarily from tensile membrane action (TMA). Reinforcement fracture during the CMA phase was observed in some specimens, underscoring the need for predictive methods that explicitly account for this phenomenon. Two simplified approaches for predicting the full load-deflection response were also presented: a finite element (FE) model and an analytical approach extending an existing framework. The FE model showed good agreement with the experimental results, accurately capturing peak resistance and reinforcement fracture. The analytical model provided satisfactory predictions, particularly during the CMA phase. Artikel i vetenskaplig tidskrift 2026-07-23 16:16:17 https://research.chalmers.se/publication/553082 2026-07-23T16:16:17Z Carbon-intensive industries account for a quarter of global annual CO2 emissions. Achieving mandated climate targets requires rapid deployment of decarbonization technologies in these industries. Such deployment typically involves substantial upfront investments amidst technical, economic, and policy uncertainties. Consequently, careful selection of decarbonization technologies or a combination thereof, coupled with measures such as process electrification and energy efficiency, is crucial.This thesis presents limitations in existing methodological approaches for comparing decarbonization pathways, spanning systems-, plant-, and site-level considerations. A generalized assessment framework was developed that addresses these limitations, with individual methodological frameworks developed in the appended papers. At the system level, extended boundaries and exergy as a metric were used to compare two CO2 capture technologies with inherently different heat and electricity demands per unit of CO2 captured, considering the perspectives of both plant owners and end-users. At the plant level, an iterative exergy-pinch analysis, combined with techno-economic analysis, was developed to identify promising process modifications in unabated process plants that maximize overall exergy utilization and CO2 avoidance, leading to successive designs towards net-zero emissions. At the site level, a site-specific techno-economic analysis was developed by incorporating quantitative and qualitative site-specific factors expected to influence the choice of decarbonization technologies. Finally, to address deployment barriers for low-emissions hydrogen, an integrated system of complementary production technologies was evaluated using a generalized optimization framework, enabling cost-optimal supply strategies under site constraints and market uncertainties. The frameworks were demonstrated in case studies on bio-CHP in a district heating system, propane dehydrogenation, and a steam cracker plant.The case study results show that integrating amine-based CO₂ capture with industrial heat pumps in bio-CHP plants could enable greater district heat delivery and provide product flexibility across heat, power, and CO₂ emissions. The iterative exergy-pinch analysis applied to the propane dehydrogenation plant identified an unconventional process modification, resulting in a substantial reduction in CO2 avoidance cost (58–70%) compared to CO2 capture from its highly diluted flue gas stream from the unmodified process. The site-specific techno-economic analysis revealed that incorporating site-specific cost factors yields higher avoidance cost estimates than standardized assessments, underscoring the risk of suboptimal technology selection. Finally, the integrated hydrogen production system demonstrated how combining multiple distinct production technologies can reduce costs, improve operational flexibility, and system redundancy. In summary, the generalized assessment framework, combining these individual framework methodologies, provides a comprehensive early-stage indication of the optimal decarbonization pathway for specific industrial sites. Doktorsavhandling 2026-07-23 16:12:11 https://research.chalmers.se/publication/548169 2026-07-23T16:12:11Z Substantial amounts of low-emissions hydrogen are required to enable CO2 emissions reduction and circularity in the petrochemical sector. However, large-scale deployment remains constrained by the persistent cost gap with fossil-derived hydrogen, the limited availability of low-cost renewable electricity and critical infrastructure, as well as the distinct operational constraints of hydrogen production technologies. This work addresses these barriers through technology diversification and integration of hydrogen production technologies. An integrated hydrogen production system is introduced that combines autothermal reforming with carbon capture and storage (ATR-CCS), solid oxide electrolysis cell (SOEC), and ammonia cracking (AC). A modeling framework is developed, centered on a mixed-integer linear programming model with a 1-year hourly resolution to optimize the technology mix and system operation while accounting for site-specific constraints and varying price conditions. The framework is demonstrated through a case study of a steam cracker plant, where integration provides opportunities to reduce hydrogen production costs via exports of displaced fuel gases. The results demonstrate how integrating multiple hydrogen production technologies reduces production costs while enhancing operational flexibility and system redundancy, compared with standalone systems. Scenario analysis highlights the importance of hedging against price uncertainty by deploying comparable or excess capacities across technologies to enable flexible operation. Based on these findings, a stepwise deployment strategy is proposed, outlining the timely implementation of individual technologies aligned with projected emissions allowance prices. The developed framework can be adapted to other clusters to identify cost-optimal, site-specific configurations for various market conditions, and thereby derive robust deployment strategies for scaling up low-emissions hydrogen production. Artikel i vetenskaplig tidskrift 2026-07-23 16:11:39 https://research.chalmers.se/publication/553084 2026-07-23T16:11:39Z Pd nanoalloys offer a spark-free, plasmonic, and highly tunable platform for H2 sensing, which is a crucial aspect of a safe hydrogen economy. Owing to a fortunate combination of thermodynamic and optical properties, Pd nanoparticles rapidly absorb H2, which induces a measurable optical shift. Pure Pd sensors suffer, however, from issues such as hysteresis during hydrogenation and CO poisoning. Alloying with Au and Cu have been found to mitigate these issues, but introduces challenges related to long-term stability and performance. The vast configurational space accessible through alloying and nanostructuring makes computational modeling an efficient route to understand and optimize nanoalloys for H2 sensing. This thesis develops multiscale models to better understand the optical and thermodynamic properties of Pd nanoalloys for H2 sensing, anchored at the atomic scale via first-principles calculations. The effect of alloying Pd with Au and Cu on the surface composition and adsorbate coverages under different environments is studied via cluster expansion models. It is found that Pd segregates to the surface in H2 and CO environments, due to strong adsorption, while Au segregates to the surface under vacuum conditions. Cu shows a more complex behavior, with a non-trivial preference for the subsurface layer under most conditions, and only modest presence in the top surface layer. The H–CO coadsorption behavior is primarily governed by the fabrication conditions, dictating whether Pd or Au segregates to the surface, while tuning the exact bulk alloy composition has only a minor effect. The experimentally observed role of Cu in mitigating CO poisoning must therefore go beyond adsorption thermodynamics, potentially by providing energetically feasible H absorption paths through the surface when the energetically most favorable paths are blocked by CO. The H sensitivity of nanodisk devices is optimized by combining atomic-scale dielectric functions with continuum electrodynamic simulations of nanoalloy structures. Single disk simulations suggest that the H-induced plasmon shift is limited by an interplay between localized surface plasmonic resonances and interband transitions. In addition, a computational platform for designing optimal nanoarray-based sensors for specific targets is presented, paving the way for future efforts in multiplexed sensor design. Doktorsavhandling 2026-07-23 16:06:51 https://research.chalmers.se/publication/549786 2026-07-23T16:06:51Z Multi-component alloys offer broad tunability for materials science applications, but are highly sensitive to operating conditions through adsorption and segregation phenomena. Here, we study Pd-Au-Cu alloy surfaces in H2 and CO environments motivated by their use in H technologies, where alloying can mitigate limitations intrinsic to Pd such as CO poisoning. To this end, we establish a framework combining machine-learned interatomic potentials trained on density-functional theory data with cluster expansions, with effectively no limitations on training set size. By constructing continuous surface phase diagrams for H-CO coadsorption, we find that adsorption under operating conditions is governed by the H coverage during the preceding annealing. Au-rich surfaces, formed under H-poor conditions, suppress both CO and H adsorption, while H-rich conditions yield Pd-rich surfaces that promote CO and H adsorption. Furthermore, Pd-rich alloy surfaces maintain higher H coverages compared to pure Pd at relevant CO partial pressures, indicating improved CO poisoning resistance. The coadsorption behavior of PdAuCu alloys is indistinguishable from that of PdAu alloys, despite experimental observations of Cu, specifically, mitigating CO poisoning. However, kinetic barriers of H sorption in dilute alloys indicate that H pathways near Au are highly unfavorable, while Cu leaves the energetics unchanged compared to pure Pd. Based on these findings and the experimental evidence, we hypothesize that alloying promotes H adsorption while Cu, specifically, preserves viable H absorption pathways in the presence of CO. Artikel i vetenskaplig tidskrift 2026-07-23 16:05:57 https://research.chalmers.se/publication/553088 2026-07-23T16:05:57Z Understanding the development of reinforcement corrosion and its effects on the service life of reinforced concrete (RC) structures remains a critical challenge, accompanied by significant uncertainties. Corrosion is one of the most prevalent deterioration mechanisms in RC infrastructure, leading to reduced structural performance, increased maintenance costs, and serious safety concerns. Previous studies have investigated the influence of corrosion on the structural response of RC members, while distributed optical fiber sensing (DOFS) has emerged as a promising technique for monitoring strains, cracking, and deflection in RC structures. Earlier research has also demonstrated the potential of DOFS-based deflection measurements for characterizing localized corrosion propagation. However, the applicability of such approaches under varying reinforcement configurations and corrosion conditions remains insufficiently understood. In this study, the serviceability response of RC beams subjected to cyclic loading and accelerated corrosion was investigated using DOFS measurements. A previously developed framework for describing corrosion propagation based on corrosion-induced deflections was validated and extended to different reinforcement diameters, bar arrangements, and corroded regions. The results showed that the framework became less accurate when corrosion was more uniformly distributed rather than localized in pits. Furthermore, a detailed analysis of the strain evolution at a representative cracked section revealed that corrosion-induced non-mechanical strains propagated throughout the cross-section until longitudinal cracking occurred. Subsequently, an apparent Young's modulus derived from sectional strain distributions proved to be a useful indicator of corrosion progression. Artikel i vetenskaplig tidskrift 2026-07-23 16:01:56 https://research.chalmers.se/publication/553069 2026-07-23T16:01:56Z The phase-field approach to brittle fracture provides a continuum framework for modeling crack initiation and propagation without explicit representation of discrete crack surfaces, provided the spatial discretization is fine enough to resolve the regularization length scale. However, uncertain local material parameters due to material defects can strongly influence simulation results, such as crack paths and remaining structural strength. At the same time, the ability to continuously monitor structures using sensors allows complementing modeling predictions with displacement measurements for example.In this contribution, we connect these two complementary sources of information and present a Bayesian inference procedure that allows updating the current model state with incoming sensor data. We construct a Bayesian prior for the model state (both displacements and phase-field) and employ an ensemble Kalman filter (EnKF) to perform the update. In the EnKF, the update is computed by performing a Kalman shift on each ensemble member. Since the standard EnKF may produce assimilated states that violate common modeling assumptions, we present a phase field-based regularization technique as a proximal step correction towards model-consistent updates. 1D and 2D numerical examples demonstrate the performance and accuracy of the proposed method and show that the updated state matches the ground truth reasonably well. Unlike traditional Bayesian inversion techniques, which have already been applied to brittle fracture, we infer not the model parameters but the model state, i.e., the displacement field and the phase-field. Although only displacements are observed, the strong correlation between both fields also allows inference of the posterior phase-field. Artikel i vetenskaplig tidskrift 2026-07-23 15:55:52 https://research.chalmers.se/publication/553091 2026-07-23T15:55:52Z Carbapenem-resistant Escherichia coli poses a serious threat to global health, with limited treatment options and potentially fatal outcomes. Beyond horizontally acquired resistance genes, other cellular pathways are remodeled in the resistant phenotype, but these systemic responses remain poorly understood. Here, tandem mass tag-based quantitative proteomics was used to characterize the response of E. coli strain CCUG 70745 to Meropenem. Two inhibitory concentrations (128 and 192 mu g/mL), anchored to the MIC of the isolate (128 mu g/mL), were compared with an antibiotic-free control after 15 min. The analysis quantified 60% of the theoretical proteome, identifying 172 and 813 differentially expressed proteins at 128 and 192 mu g/mL, respectively. Canonical resistance determinants, including beta-lactamases and efflux pumps, were altered, as well as proteins involved in cell-wall formation, membrane transport, and signal transduction. Gene set enrichment analysis highlighted oxidative phosphorylation, ABC transporters, two-component systems, and cofactor metabolism. Increased abundances of two-component-system and membrane-integrity proteins were consistent with a coordinated, dose-dependent stress response, and interaction networks linked a cell-division module to efflux and metabolic adaptation. These results suggest that Meropenem engages both primary and auxiliary resistance-associated processes, providing a proteomic framework that may guide therapies targeting bacterial metabolism and membrane functions. Artikel i vetenskaplig tidskrift 2026-07-23 15:55:30 https://research.chalmers.se/publication/553089 2026-07-23T15:55:30Z In this paper, we present the analytical and numerical study of the Lagrangian optimization approach for determining the space-dependent source function in the parabolic inverse source problem (ISP) using partial boundary measurements. The Lagrangian approach for the solution of the optimization problem is presented, and optimality conditions are derived. The proof of the Fr & eacute;chet differentiability of the regularized Tikhonov functional and the existence result for the solution of the inverse source problem are established. A remarkable local Lipschitz stability estimate for the unknown source term in terms of partial boundary measurement using the variational approach is obtained. The numerical examples justify the theoretical investigations using the conjugate gradient method (CGM) in 2D and 3D tests with noisy data. Artikel i vetenskaplig tidskrift 2026-07-23 15:45:41 https://research.chalmers.se/publication/553065 2026-07-23T15:45:41Z Prototypical catalysts are realized as metal nanoparticles supported on a metal-oxide. It is well-known that the choice of support may have significant consequences on the catalytic activity, also in cases where the reaction is believed to occur on the metal phase. The underlying reason for this metal/oxide synergy is poorly understood, and often attributed to processes occurring at the metal/oxide interface. Here, we use density functional theory calculations to investigate the synergy between metal nanoparticles (Cu, Pd, Pt, and Au) and oxide supports (ZnO, MgO and ZrO2) in the case of hydrogen (H2) adsorption. The presence of a metal phase favors the formation of OH-groups in the oxide surface owing to a significant oxide-to-metal charge transfer, effectively charging the metal nanoparticles. The phenomenon is general and the hydrogen adsorption energy depends on the choice of oxide. For Cu, Pd, and Pt supported on ZnO, we find that the presence of a metal nanoparticle is crucial for the kinetics of H2 adsorption. H2 dissociates on the metal and occupies the oxide sites via a spillover mechanism. The hydrogen-induced charging of metal particles and formation of OH-groups advance the understanding of composite metal/oxide systems, with implications for catalytic properties. Artikel i vetenskaplig tidskrift 2026-07-23 15:44:06 https://research.chalmers.se/publication/553085 2026-07-23T15:44:06Z Policies and strategies to improve environmental sustainability in cities and regions have often focused on a single sector, subsystem or impact category, or a small number of them, limiting their potential to effectively reduce overall environmental impacts. Comprehensive frameworks are needed to adequately assess environmental impacts and to identify hotspots, trade-offs and opportunities with substantial improvement potential. This article introduces a systematic framework to calculate the potential life-cycle environmental impacts of consumption at the regional and city levels. The framework is applied to the Autonomous Province of Trento and its capital city, Trento, in northern Italy. The framework draws on (i) a state-of-the-art methodology combining urban metabolism and life-cycle assessment, which estimates cradle-to-gate environmental impacts of urban consumption, and (ii) the EU Consumption Footprint methodology, which estimates cradle-to-grave environmental impacts of household consumption. First, we develop a material flow accounting model to estimate annual consumption of thousands of product types. Second, we select a set of representative product types based on their relative mass consumption shares and on their potential environmental impacts, as identified in existing research, to ensure relevant coverage across all consumption areas. Third, we develop a cradle-to-grave life-cycle model to assess the potential environmental impacts of consumption across a broad range of impact categories. Cradle-to-grave and cradle-to-gate results are compared, highlighting the importance of a cradle-to-grave perspective, including food, buildings and transport, which contribute significantly to the overall impacts associated with regional and urban areas. This comprehensive and systematic framework can support more effective and integrated decision-making by comprehensively addressing consumption-driven environmental impacts of cities and regions across the full life cycle. Artikel i vetenskaplig tidskrift 2026-07-23 15:40:28 https://research.chalmers.se/publication/553073 2026-07-23T15:40:28Z The peroxisome proliferator-activated receptor alpha (PPAR alpha) is a key regulator of lipid metabolism and energy homeostasis. However, its role in shaping the gut microbiota requires further investigation. Therefore, the aim of the present study was to investigate whether the lack of PPAR alpha in a mouse model or the presence of a single nucleotide polymorphism (SNP) rs6008259 of PPAR alpha in humans can modulate the gut microbiota and its association with metabolic alterations. PPAR alpha-/- and PPAR+/+ male mice were fed an AIN-93 diet for 10 days, and a human cohort (n = 177) was genotyped for the PPAR alpha SNP rs6008259. PPAR alpha-/- mice showed less body weight gain, more fat mass and reduced lean mass compared to WT, despite similar food intake. They exhibited elevated hepatic triglycerides and hyperlipidemia. In humans, carriers of the rs6008259 allele of PPAR alpha showed similar findings in blood lipids and body composition. Colonic analysis revealed reduced hypoxia in PPAR alpha-/- mice, increased inflammatory markers, and compromised barrier function. Gut microbiota analysis in PPAR alpha-/- mice and humans, carriers of the rs6008259 allele of PPAR alpha showed reduced alpha diversity and altered composition, including increased Blautia, Parabacteroides and Lanchoclostridium. Genetic background is important in the interpretation on the effects of diet on gut microbiota. Artikel i vetenskaplig tidskrift 2026-07-23 15:37:54 https://research.chalmers.se/publication/553083 2026-07-23T15:37:54Z Accurate forecasting of large earthquakes is of great importance, yet most current earthquake forecast evaluation metrics, such as the log-likelihood score, do not give additional weight to large-magnitude events. To this end, magnitude-weighted goodness-of-fit scores for earthquake forecasting have recently been introduced, such as potency-weighted log-likelihood and the -score. In this article, we investigate properties of the -score, which is a quotient emphasizing model fit for the largest 5% of earthquakes. We explore the theoretical properties of the -score, demonstrating that under certain null conditions, the expectations of the numerator and denominator are equal and thus the expectation of is 1 in a ratio sense. Additionally, the score satisfies a law of large numbers. We evaluated the -score of 21 next-day gridded earthquake forecasts for California, provided by the Collaborative for the Study of Earthquake Predictability (CSEP) for the years 2012, 2014, and 2017. We also calculate the log-likelihood scores of the forecasts to obtain a more comprehensive evaluation of how well different models perform, both for predicting the largest events and also in terms of overall model fit. Artikel i vetenskaplig tidskrift 2026-07-23 15:34:42 https://research.chalmers.se/publication/553066 2026-07-23T15:34:42Z The languages of mathematical physics and modelling are endowed with a rich "grammar of dimensions" that common abstractions of programming languages fail to represent. We propose a dependently typed domain-specific language (embedded in Idris) that captures this grammar. We apply it to formalize basic notions of dimensional analysis: those of dimension function, physical quantity, homomorphic measurement, the covariance principle and Buckingham's Pi theorem. We hope that the language makes mathematical physics more accessible to computer scientists and functional programming more palatable to modellers and physicists. Artikel i vetenskaplig tidskrift 2026-07-23 15:32:39 https://research.chalmers.se/publication/553067 2026-07-23T15:32:39Z With the growing demand for data traffic, new types of optical fiber have been proposed to address the capacity crisis of existing single-mode fiber infrastructure. Space-division multiplexed (SDM) systems promise to exploit multiple spatial channels for parallel data transmission. The aim of this study is to provide a systematic approach to experimentally investigate the fluctuations of random coupling in the temporal domain of coupled multi-core fibers (MCFs). Understanding these temporal dynamics is crucial to setting requirements for digital signal processing and to developing robust signal recovery algorithms. This is also the first step towards dynamic channel models of these fibers. One of the key requirements for untangling the signals after transmission is accurate knowledge of channel behavior in both the time and frequency domains. We present a statistical and experimental analysis of the temporal dynamics of random coupling in strongly coupled MCFs. Based on a statistical time-drift model, we have experimentally characterized the temporal response of coupled MCFs and their statistical properties, such as the temporal autocorrelation function and the probability density function of fractional optical power. Artikel i vetenskaplig tidskrift 2026-07-23 15:26:42 https://research.chalmers.se/publication/553077 2026-07-23T15:26:42Z Sustainable bio-based and biodegradable materials are receiving increased attention in response to the environmental impact of conventional non-biodegradable plastics. Thermoplastic starch (TPS) and poly(butylene succinate-co-adipate) (PBSA) are bio-based and biodegradable materials that have the potential to serve as an alternative solution in the disposable packaging sector. The melt processing of TPS is, however, challenging due to its moisture sensitivity and rapid aging. This study investigates the development of TPS/PBSA blends without compatibilizers, comparing a conventional two-step processing method with a one-step approach combining starch plasticization and its blending with PBSA. The one-step process exhibits higher stability, making it a promising candidate for industrial applications due to its reduced energy consumption and production costs. To contribute to waste reduction, disintegration in industrial composting and multiple cycles of mechanical recycling were performed. Artikel i vetenskaplig tidskrift 2026-07-23 15:24:32 https://research.chalmers.se/publication/553086 2026-07-23T15:24:32Z NH3/H2 flames are a promising route to carbon-neutral combustion, yet their turbulent burning rates remain poorly characterized. Using simultaneous PLIF of NH3, NH and OH together with Rayleigh scattering in a jet flame stabilized on a McKenna burner, we show that conventional flamelet-based turbulent burning velocities (UT,F) drastically underestimate the true bulk consumption velocity (UT), by factors of up to 25× and 9× when evaluated from NH3- and OH-PLIF data, respectively. To overcome this limitation, we introduce a new bulk metric U*T, derived from the strong NH–heat-release-rate correlation observed in unstretched laminar simulations; it inherently accounts for reaction-zone broadening, stretch and flame–flame interactions. U*T substantially exceeds UT,F, with the residual gap to UT traced to the breakdown of NH–HRR proportionality under strain. The framework also yields local burning velocities u*c that grow with downstream distance, providing a physically motivated, semi-quantitative characterization of highly turbulent NH3/H2 combustion. Artikel i vetenskaplig tidskrift 2026-07-23 13:35:14 https://research.chalmers.se/publication/553060 2026-07-23T13:35:14Z According to the equivalence principle, acceleration cannot be distinguished from a gravitational field in the opposite direction. Although conceptually different, using inertial forces in a consistent way gives mathematically equivalent descriptions of the interactions required for acceleration. However, we find that while most new students have learned to avoid ‘centrifugal forces’, many of them are still tempted to draw or choose force diagrams including an outward force in some cases of circular motion, but referring to a ‘centripetal force’, and many others prefer a diagram with a centripetal force as a real force. Invoking the weak equivalence principle, which applies to objects with mass, can be a way to connect students’ bodily understanding with formal mechanics. In this way embodied experiences of acceleration during everyday life, sports and play can be used as resources for conceptual understanding. Including kinetic diagrams in the construction of free-body diagrams is a reminder that force equilibrium does not apply for accelerating bodies. The weak equivalence principle is a consequence of classical mechanics. It inspired Einstein to develop the general theory relativity. Artikel i vetenskaplig tidskrift 2026-07-23 13:30:39 https://research.chalmers.se/publication/553050 2026-07-23T13:30:39Z The increasing complexity of large-scale infrastructure projects presents significant challenges and specifically challenges in Systems Engineering (SE) activities, particularly in managing vast volumes of data, evolving stakeholder requirements, and maintaining traceability across long project lifecycles. This study explores the potential of Artificial Intelligence (AI), particularly tools based on Natural Language Processing, to support SE practices in infrastructure contexts. Through a combination of survey data, two pilot studies, and five semi-structured interviews conducted within the Swedish national transport administration, the research investigates how AI can improve system information management, assist with Systems Engineering tasks, and what practical barriers limit broader adoption. Findings indicate that AI tools show promise in supporting text-heavy SE tasks such as document summarization, requirement tracking, and assumption analysis. However, low organizational awareness, trust concerns, lack of integration into workflows, and restricted access to internal data due to security concerns significantly limit their current impact. The study concludes by recommending targeted organizational strategies, operational support roles, and structured experimentation to unlock the full potential of AI in supporting SE in large-scale infrastructure projects. Paper i proceeding 2026-07-23 13:06:44 https://research.chalmers.se/publication/c80be7d2-e4b2-46fd-8f3a-54d1c481bb47 2026-07-23T13:06:44Z Low-frequency radio polarimetric observations provide a powerful probe of magnetic fields in astrophysical sources and the intervening medium, as well as magnetospheric emission from compact objects such as pulsars, magnetically active stars, brown dwarfs, and planetary aurorae. With baselines of up to 2000 km, LOFAR offers a unique opportunity to study the low-frequency polarized Universe at sub-arcsecond resolution. However, polarimetric studies with LOFAR have so far been limited to angular resolutions of (Formula presented), resulting in stronger beam depolarization. Here, we present a calibration strategy that enables full-resolution polarimetric imaging with the LOFAR pan-European array. Our method applies full-Jones corrections to the international stations using an in-field unpolarized calibrator. In addition, when a sufficiently bright polarized source is present in the field, multi-epoch observations can be aligned in Faraday depth using a visibility-based correction that accounts for polarization angle and rotation measure offsets. This approach enables deeper combined imaging and deconvolution. We apply this strategy to the LOFAR ELAIS-N1 field, combining four 8-h observations for a total integration time of 32 h. At (Formula presented) resolution, we detect two previously known polarized sources identified in lower-resolution studies, resolve additional polarized components, and localize emission regions with sub-arcsecond precision. We also identify a new polarized source and detect circularly polarized emission from the binary M-dwarf system CR Draconis, measuring its proper motion across epochs. These results demonstrate that sub-arcsecond polarimetry at metre wavelengths is now feasible with LOFAR, opening new science opportunities in the LOFAR2.0 era. Artikel i vetenskaplig tidskrift 2026-07-23 11:55:51 https://research.chalmers.se/publication/552805 2026-07-23T11:55:51Z