As hydrogen gains momentum as a clean and versatile energy carrier for decarbonizing hard-to-abate sectors, ensuring the safety of hydrogen infrastructure becomes critical for its widespread adoption. This review draws on peer-reviewed literature, industrial reports, and international standards for hydrogen technologies. It systematically examines safety risks across the hydrogen value chain, from production to end-of-life and assesses the effectiveness of existing mitigation strategies as well as identifying key research gaps. Common risks such as hydrogen leaks, over-pressurization, and material degradation are present at nearly every stage. Less frequent but potentially severe hazards include the risk of ice formation or equipment damage from cryogenic hydrogen leaks, and toxic exposures from chemical carriers like ammonia or hydrides used for hydrogen storage and transport. The mitigation technologies evaluated include leak detection systems, quick-release valves, emergency ventilation, and both material-based and physical barrier systems. While these safety solutions provide considerable protective potential, their long-term effectiveness depends on real-time responsiveness, and regulatory enforcement. The review also highlights critical gaps in predictive modeling, material durability under extreme conditions exacerbated by climate change, and human error analysis. Emerging technologies, such as AI-enabled safety systems and digital twins, remain underexplored, and current hydrogen safety frameworks have a limited understanding of hydrogen combustion behavior and effective fire suppression strategies. To support the safe and scalable deployment of hydrogen infrastructure, the study calls for targeted research, stakeholder education, and harmonized safety standards. This review provides a timely synthesis of risks and controls to guide future development, policy, and innovation in hydrogen safety. This review will support industry stakeholders, and researchers in developing safer, more reliable, and standardized hydrogen infrastructure.

Non-destructive quantification of the internal progression of thermally induced degradation in wood using X-ray imaging is challenging because the material is inherently heterogeneous and the resulting intensity changes are small, spatially variable, and influenced by acquisition noise and partial-volume effects. A measurement framework was developed for quantifying combustion-front penetration in wood using time-resolved X-ray computed tomography (CT) during controlled one-sided heating. The focus was on defining and measuring the combustion front in CT data rather than detailed physical interpretation of underlying material transformations. A CT-compatible heating arrangement enabled repeated volumetric scanning without interrupting thermal exposure. An automated voxel-wise analysis pipeline was implemented, including baseline normalisation using robust median-based statistics, formation of depth-dependent profiles along the heating direction, and threshold-based front detection with sub-voxel interpolation. Measurements were evaluated within a fixed three-dimensional region of interest located approximately 10 mm inside the specimen boundaries to reduce edge effects and ensure reproducible spatial sampling. Validation against post-exposure visual assessment showed reliable front detection only when a statistically coherent volumetric signature was present. Application to a dynamic experiment enabled extraction of a representative propagation rate of 0.92 mm min⁻¹.

This study presents a multiscale investigation of mycelium-based biocomposites produced via solid-state cultivation of Ganoderma lucidum on agro-food sidestreams. Three lignocellulosic residues, wheat bran (in two particle sizes), rice straw, and spent coffee grounds, were selected based on global availability and chemical diversity. The biocomposites were characterized to investigate how substrate composition and mycelial growth influence microstructure and macroscopic performance.

Monosaccharide analysis and scanning electron microscopy (SEM) revealed that wheat bran supported enhanced mycelial growth. Fine wheat bran-based composites exhibited compressive strengths up to 449 kPa at 30 % strain and tensile moduli of 15–25 MPa, significantly higher than expanded polystyrene (EPS), a conventional insulator. All biocomposites showed intrinsic surface hydrophobicity (water contact angles of 106–120°). Thermal analyses, including thermogravimetric analysis (TGA) and hot-plate conductivity measurement, confirmed their suitability as porous insulation. Cone calorimetry demonstrated improved fire safety in wheat bran-based composites, with reduced peak heat release rates (112–115 kW/m2).

Embodied energy and carbon footprint assessments indicated up to 89 % lower energy demand and 72 % lower CO2 emissions compared with EPS. Through multiscale characterization and direct benchmarking, this study shows how substrate selection and fungal-substrate interactions can be utilized to tailor performance. The findings provide insights into converting low-value biomass into scalable, fire-safer, and environmentally responsible insulation materials.

Polymer-based composites have gained prominence in tribological applications due to their lightweight nature, tunable properties, and multifunctional potential. However, existing reviews largely report performance improvements without systematically addressing contradictory trends, testing variability, and emerging manufacturing routes. This review analyses friction and wear mechanisms in fibre-reinforced and particle-reinforced polymers, surface coatings, and additively manufactured polymer composites. Key mechanisms, including load transfer, transfer film formation, thermal dissipation, and interfacial effects, are critically synthesised across thermoset and thermoplastic systems. Representative performance trends are discussed to highlight the influence of reinforcement type, processing route, and operating conditions, along with limitations in current tribological testing practices and the need for standardisation. By integrating mechanistic understanding with comparative performance and future research priorities, this review provides guidance for the design and evaluation of polymer composites in automotive, aerospace, marine, and biomedical tribological applications.

To elucidate the dispersion and explosion characteristics of multi-metal powder and liquid composite fuel formulations, high-energy metal powders (aluminum (Al), boron (B), and magnesium hydride (MgH₂)) are incorporated into a liquid fuel primarily composed of diethyl ether (DEE) and isopropyl nitrate (IPN). The explosion characteristics of different solid-liquid fuel-air-explosive (FAE) under unconfined conditions are investigated using a high-speed camera, infrared thermal imaging, and a pressure measurement system. Results demonstrate that high-energy metal powders significantly enhance detonation energy dissipation, with aluminum exhibiting the most pronounced effect. Fuel 5# (45.4 wt% DEE, 9.2 wt% IPN, 29.5 wt% Al, 9.1 wt% B, 6.8 wt% MgH₂) exhibits superior explosion performance, achieving higher values of overpressure, impulse, and thermal radiation damage during the detonation stage compared to other fuels. However, Fuel 5# also displays faster decay rates, attributed to accelerated heat release rates induced by B and MgH₂ powders. This study reveals that different metal powders in solid-liquid FAE exhibit distinct enhancements in explosion performance, providing critical insights for optimizing composite fuel design.

The integration of sustainable waste-derived reinforcements into polymer composites is an effective strategy for improving performance while reducing environmental impact. In this study, rice husk biochar was investigated as a particulate reinforcement for epoxy composites, and its influence on mechanical, tribological, and thermal behaviour was systematically evaluated. Epoxy composites containing different weight fractions of rice husk biochar were fabricated and characterised. Tensile strength increased from 22.7 MPa for neat epoxy to 29.2 MPa at 9 wt.% biochar, accompanied by an increase in elongation at break from 0.8% to 1.31%, indicating improved stress transfer and reduced brittleness. Flexural strength similarly improved from 58 MPa to 70.1 MPa, confirming enhanced resistance to bending-induced failure. Fracture-surface analysis revealed suppression of cleavage-dominated river patterns and increased crack deflection in biochar-reinforced composites. Dry sliding wear analysis showed that intermediate biochar content increased wear mass loss (0.76 mg at 6 wt.%) due to particle pull-out and third-body abrasion, whereas higher filler loading promoted more stable surface interaction. Thermogravimetric analysis demonstrated improved thermal stability of biochar-reinforced epoxy composites at elevated temperatures, particularly in the 400 °C–550 °C range, attributed to char-mediated thermal shielding. Overall, the results demonstrate that rice husk biochar provides multifunctional enhancement of epoxy composites by improving mechanical performance and high-temperature thermal resistance, while introducing content-dependent tribological effects, highlighting its potential as a sustainable reinforcement for epoxy-based non-load bearing structural applications.

A novel family of lignin-based thermosets that rely on acetal linkages and do not release hazardous compounds during degradation is proposed as future circular design materials. Poly(ethylene glycol) diisopropenyl ether (PDIP) was utilized as a soft segment to form the acetal linkage with the lignin hydroxyl groups via the addition reaction to the isopropenyl double bond. The use of PDIP instead of previously utilized poly(ethylene glycol) divinyl ether (PDV) prevents the release of harmful acetaldehyde during the acidic hydrolysis of the materials. In addition to the lower toxicity of the degradation products, thermosets with PDIP are more resistant to acidic hydrolysis. Characterization of the thermosets by thermal analysis revealed that the merits of this new lignin-PDIP thermoset extended to increased thermal stability, with Td5%, Td30%, and Ts values of 243–253, 349–363, and 152–155 °C, respectively. Furthermore, the developed materials demonstrated intrinsically lower flammability and reduced heat release potential, paving the way for safer materials with a reduced need for potentially harmful flame retardants. The ease of synthesis and high yields achieved encourage further work toward circular and safe materials solutions based on lignin and PDIP.

The growth of hydrogen infrastructure in Sweden requires navigating a complex permitting landscape. This overview examines the Swedish permitting process for hydrogen-related projects. Key national laws include the Environmental Code (Miljöbalken) for environmental permits, the Seveso Act on major accident prevention, the Flammable and Explosive Goods Act, and the Work Environment Act for occupational safety. The classification of projects under the Swedish Environmental Code determines which authority is responsible for the permit assessment. In this overview, each stage of the consultation and permitting process, from early project planning and stakeholder consultations through application submission, environmental impact assessment (EIA), public notification, and decision are outlined. 

There have been investigations in environmental permit processes in Sweden. Earlier proposals from these investigations, such as SOU 2022:33, focused on improving coordination between authorities and strengthening capacity through a climate permit taskforce. These measures aimed to streamline the handling of climate-related projects such as hydrogen without weakening environmental protection. More recently, SOU 2024:98 proposes a broader restructuring of Sweden’s permitting framework. The inquiry suggests a more unified system, including clearer environmental assessment procedures, strengthened time-management requirements, and a more coordinated organisation for permitting. These changes will respond to persistent challenges such as long processing times and uneven practices across authorities. 

The report discusses these challenges and compares Sweden’s approach with fast-track hydrogen permitting initiatives in Germany and the Netherlands. Together, the findings indicate that while current Swedish regulation maintains strong environmental integrity, further simplification and clearer guidance will be important to accelerate hydrogen investments in line with Sweden’s 2045 climate goals.

Understanding and alleviating energy poverty is critical for sustainable development. This study harnesses a suite of Machine Learning (ML) algorithms to predict Multidimensional Energy Poverty Index (MEPI) and to highlight the spatial distribution of energy poverty. We assess the predictive accuracy of Random Forest (RF), Support Vector Machine (SVM), Artificial Neural Network (ANN), Multiple Linear Regression (MLR), and XGBoost models. The RF model outperforms others, achieving an R2 value of 0.92 and a Pearson Correlation Coefficient (PCC) of 0.97 on the testing dataset, indicative of a highly accurate prediction capability. XGBoost also demonstrates strong predictive power with corresponding values of 0.88 and 0.94, respectively. Our spatial analysis, revealing significant clustering of energy poverty with a Global Moran’s I value of 150.39, indicates that energy poverty is not only geographically concentrated but also intricately linked to socio-economic factors such as income levels, access to education, and nutritional status. These insights underscore the necessity of region-specific and socio-economically informed policy interventions. The results inform targeted interventions, particularly highlighting the critical roles of education and nutrition in mitigating energy poverty. The RF model’s accuracy rate of 92% on the testing set suggests that improvements in these sectors could significantly influence MEPI scores. The integration of ML and spatial analysis offers a nuanced and actionable understanding of energy poverty, paving the way for targeted, evidence-based policy formulation aimed at achieving SDG7: ensuring access to affordable, reliable, sustainable, and modern energy for all.