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Analysis of elastic and plastic behaviour in untreated pine wood under scratch test loads combining X-ray computed tomography and finite element simulations
No full textWood is an anisotropic material, which affects its performance under different loading conditions. To understand the origin of surface failures occurring in wood under mechanical disintegration loads, an accurate investigation of its elastic and plastic behaviour is required. This study introduces a methodology that integrates experimental scratch testing, X-ray micro-computed tomography (μCT), and finite element simulations to examine the elastic and plastic deformation and failure behaviour of untreated pine wood under scratch loading. In the existing literature, scratch testing is primarily employed to assess coating adhesion or material abrasion resistance; its use for probing the mechanical response of wood remains limited. In the present study, scratches were applied to pine specimens in the radial, tangential, and longitudinal directions of wood using a diamond indenter under constant normal loads perpendicular to the scratched surface. The permanent residual depths measured by μCT were compared with FE-predicted deformations. The selected methodology enables quantification of the relationship between wood structure, loading conditions, and scratch performance. The results demonstrated that the regions with higher density favoured elastic deformation, whereas the residual scratch depth, reflecting plastic deformation, provided a reliable indicator of scratch resistance, exhibiting higher scratch resistance for the higher density wood. In particular, the wood with higher density showed residual depths in the range of 53–144 µm in radial direction scratches, whereas the less dense wood showed values between 90 and 300 µm. μCT imaging also revealed detailed deformation mechanisms and fracture pathways that develop under scratch-type loading. By coupling μCT with FE modelling for wood scratch mechanics, the work deepens the understanding of how wood microstructure responds to different scratch loading conditions. The findings can serve as a scientific reference for future experimental and numerical investigations of scratching, cutting and other disintegration loads in untreated wood and wood-based composites at the microscale.</p
Economic feasibility assessment of calcium looping energy storage and carbon capture with multi-market modelling approach
No full textLong-duration energy storage is essential for renewable energy systems due to increasing variability in power grids. This study evaluates the techno-economic feasibility of a potential technology, calcium looping thermochemical energy storage (CaL TCES), within the Finnish electricity market, employing the multi-market modelling tool Predicer. The objective of the study is to improve economic feasibility assessment of CaL TCES by optimizing the system's participation in multiple electricity markets. A case study is explored where CaL TCES is integrated into a biomass combined heat and power (CHP) plant for both energy storage and carbon capture. Results show that participation in both spot day-ahead and manual frequency restoration reserve (mFRR) markets increases operational hours, and revenue compared to spot market participation alone, with electricity market revenue increasing 56% and 79% in 2023 and 2024, respectively. Despite this, the net present value (NPV) remains negative. The break-even selling price of electricity (BESP) was 463 €/MWh, with an NPV of −115 M€. Investment costs dominate lifetime costs, even with potential reductions through industrial integration. Revenues from CO2 utilization and district heat exceed those from the electricity market, highlighting that electricity market revenues alone are insufficient for economic viability. Sensitivity analyses suggest that profitability could be achieved with simultaneous changes in several economic components: 30% decrease in CAPEX and OPEX, increases in electricity market and district heating revenues, a lower electricity tax and discount rate. In conclusion, while CaL TCES has potential for retrofit applications, significant cost reductions are necessary for profitability in renewable energy-based systems like Finland's.</p
Review of existing data-driven initiatives and their relevance on plastics circularity
Full text linkThis research report explores how data-driven solutions could be transforming the circularity of plastics, emphasizing the growing importance of digital tools, standards, and regulatory frameworks in enabling sustainable practices across the plastics value chain. The report begins by clarifying the concept of data in the circular economy, highlighting its role in transparency, traceability, and informed decision-making. It notes that data can range from broad annual recycling statistics to granular, real-time process measurements, and stresses that high-quality, well-managed data is becoming essential for compliance and competitiveness, especially as new EU regulations demand detailed product and material information.The document reviews the current state of data-driven initiatives, such as Digital Product Passports (DPPs), which are being piloted in sectors like batteries and textiles. These passports compile lifecycle data to enhance transparency and support circular business models. The report also discusses advanced technologies that optimize polymer production and recycling, as well as machine vision and robotics for waste sorting.A part of the report is dedicated to standards and certification systems, such as ISCC PLUS, which ensure traceability and sustainability in recycled plastics. Recent European standards now differentiate between sorted plastics and recyclates and introduce classifications like Data Quality Levels (DQL) for digital trading, paving the way for broader adoption of Digital Product Passports.Cross-sectoral insights are provided, showing how data-driven circularity is being applied in electronics, food, and agriculture. The report highlights the evolution of data sharing technologies, the opportunities and challenges they present including privacy, security, interoperability and the regulatory landscape shaped by the EU Data Act, Data Governance Act, and Corporate Sustainability Reporting Directive (CSRD).Ultimately, the report concludes that robust data frameworks and collaborative data ecosystems are foundational for advancing plastics circularity. Organizations that invest in these areas will be best positioned to meet regulatory requirements and market demands, driving the transition to a more circular and sustainable economy. However, their success depends on thoughtful implementation, harmonized standards, and a clear strategic purpose for data collection and processing
Depolymerisation of γ-Valerolactone Organosolv Lignins with Unsupported Molybdenum-Based Catalysts
No full textLignin is an attractive feedstock for a wide variety of applications ranging from aromatic chemicals and transportation fuels to resins and coatings. Emerging biorefinery concepts, like the organosolv process, enable the separation of all the lignocellulose components, and moreover, produce lignins of high quality and purity susceptible to valorisation by depolymerisation. In this work, we focus on the depolymerisation of lignins obtained by γ-valerolactone (GVL) organosolv fractionation of four biomass feedstocks, eucalyptus, white birch, sugarcane bagasse and Scots pine. We demonstrate that lignins extracted with the GVL process are depolymerised using unsupported molybdenum-based catalysts under reductive conditions in supercritical ethanol. As a result, over 90% yields of low-molecular-weight lignin oils are obtained with minimal char formation, yields of the aromatic monomers being 7–16 wt%. Furthermore, the design of experiments method is used to analyse the effect of depolymerisation conditions, catalyst, hydrogen loading and temperature, on the yields and properties of the product fractions. Notably, we show that the properties of the lignin oils and monoaromatics can be tuned towards the targeted application by modifying the depolymerisation conditions.</p
Study of Isolation Improvement of Antenna Arrays for D-band Transceiver
No full textThis paper presents an experimental study evaluating the efficiency of various isolation techniques for antenna arrays in the D-band. The influence of antenna polarizations, the distance between the arrays, presence of absorbing materials and metal shield on isolation is studied. The study demonstrates that isolation of up to 80-85 dB between transmitting and receiving antenna arrays in the D-band can be achieved
Advances in biomaterials for medical textile applications:a review on integration strategies and sustainable innovations
No full textBiomaterials have undergone remarkable evolution over recent decades, driven by advances in molecular design, synthesis techniques, and functional optimization. These innovations have transformed biomedical applications, addressing critical global healthcare challenges. Early-career researchers have played a pivotal role in this progress through interdisciplinary approaches and novel methodologies. This review provides a systematic assessment of biomaterials in medical textile applications, covering performance characteristics, fabrication strategies, and emerging eco-friendly alternatives. It highlights recent interdisciplinary developments and innovative concepts not addressed in previous literature, offering new perspectives to guide future research in biomedical textiles. Furthermore, the review presents an in-depth analysis of biomaterial-based approaches for medical textiles, emphasizing strategies for next-generation functional polymers. Medical textiles, essential in clinical practice, demand stringent properties such as biocompatibility, mechanical strength, and functionality. Applications include wound dressings, implants, surgical sutures, and drug delivery systems. Incorporating advanced biomaterials into these textiles has improved therapeutic efficacy, patient outcomes, and sustainability. This paper evaluates the performance of various biomaterials, explores innovative fabrication and functionalization techniques, and discusses eco-friendly alternatives to overcome limitations of conventional materials. Ultimately, the review underscores the potential of biomaterial-enabled medical textiles in shaping personalized and regenerative healthcare.</p
High-Throughput Computational Screening, Non-Metallic Inclusion Analysis, and Microstructural Characterization of a Novel Medium Manganese Steel
No full textHigh-throughput computational screening (HTCS) based on CALPHAD (Calculation of Phase Diagram) was employed to investigate potential chemical compositions within the medium manganese steel family for achieving desired austenite stability and stacking fault energy (SFE). The primary objective was to identify optimal alloy compositions that balance the complex effects of various alloying elements on retained austenite fraction and related mechanical properties. Utilising TC-Python Thermo-Calc software coupled with a custom-developed algorithm, two optimised compositions were determined: 0.35C, 9Mn, 1Mo, 3Al, 1Si, 0.05Nb, 0.3V (alloy 353), and 0.35C, 9Mn, 1Mo, 3Al, 1Si, 0.1Nb (alloy 310) in wt.% to be the best fited composition to our selected criteria. The alloys were subsequently produced via open-air induction furnaces, and the microstructure was analysed after the hot forging condition. The initial multiphase as-cast structure, primarily composed of lath martensite, δ-ferrite (34 vol.%), and retained austenite (RA, 5–7 vol.%), experienced notable grain refinement. Forging reduced δ-ferrite grain sizes from 39 µm to 12 µm (alloy 310) and from 46 µm to 9 µm (alloy 353), accompanied by increased RA content (28 vol.% for alloy 310 and 46 vol.% for alloy 353) and reduced RA grain sizes (1.2 µm and 1.9 µm, respectively). Non-metallic inclusions (NMIs) were analysed using field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, classifying inclusions primarily as AlN, MnS, (Mo,Nb)C, or their combinations. No significant differences in inclusion types were observed, but forged samples displayed reduced inclusion sizes. In summary, the results showed that HTSC effectively identified optimal compositions with a high fraction of retained austenite.</p
Crystal plasticity modelling of carbide network effects on microstructural strain localization and fracture behaviour in bainitic steels
Full text linkVarious steel microstructures contain carbides that are designed to enhance the strength of the material. In Reactor Pressure Vessel (RPV) steel, the carbides are an inherent part of the microstructure, finely distributed throughout the grains and grain boundaries. This work focuses on the investigation of the effect of carbides ranging from 80 nm to on strain and stress localization when the carbides are explicitly introduced in polycrystalline models. Two size dependent crystal plasticity finite element models are used in the investigation to evaluate their feasibility to address localization phenomena with carbide strengthened microstructures. We analysed the effects of carbides on quasi-2D Scanning Electron Microscopy (SEM) based microstructures with realistic carbide mapping, and utilized synthetic 3D computational grain-carbide microstructures to investigate spatial and shape effect of carbides. Microscale digital image correlation (uDIC) measurements show that strain localization is influenced significantly by carbide networks and carbides can promote slip in grains with low Schmid’s factor. Lastly, we demonstrated the effect of large carbides on fracture predictions using a newly developed microstructurally informed brittle fracture model, which represents a step forward compared with existing Beremin-type approaches. It was observed that carbide induced stress/strain heterogeneity alters fracture probability predictions notably
Design–Build with a Development Phase: The Underlying Theory
No full textThis study focuses on a design–build (DB) procedure that exploits the related parties’ (preconstruction) collaboration to improve the economic efficiency of construction projects. It is called design–build with a development phase (DBd). In the procedure, the owner and the selected contractor continue the development of the project solution in cooperation, adhering to the principle of benefit sharing, which is enabled by preagreed rules and the benchmark solution, formed as a result of requirement-based price-inclusive contractor selection where technical design is not included in the proposal; the formation of the final contract is a two-stage process, and a new owner decision is needed to enter the realization phase. More precisely, this study aims to discover and formulate a theory that underlies the DBd procedure that is a heuristic construct of the procedure’s origin. For that, the DBd procedure was conceptualized by determining its key elements and their relationships, and by showing how a coherent whole is achieved by the elements’ mutual interoperability. Therefore, the study contributes to the body of knowledge by crystallizing the DBd concept and its rationality. Even more importantly, the study eventually establishes the novel DBd procedure by combining consistent theoretical and practical views considering the earlier success of DBd in trial projects
Economic feasibility assessment of calcium looping energy storage and carbon capture with multi-market modelling approach
No full textLong-duration energy storage is essential for renewable energy systems due to increasing variability in power grids. This study evaluates the techno-economic feasibility of a potential technology, calcium looping thermochemical energy storage (CaL TCES), within the Finnish electricity market, employing the multi-market modelling tool Predicer. The objective of the study is to improve economic feasibility assessment of CaL TCES by optimizing the system's participation in multiple electricity markets. A case study is explored where CaL TCES is integrated into a biomass combined heat and power (CHP) plant for both energy storage and carbon capture. Results show that participation in both spot day-ahead and manual frequency restoration reserve (mFRR) markets increases operational hours, and revenue compared to spot market participation alone, with electricity market revenue increasing 56% and 79% in 2023 and 2024, respectively. Despite this, the net present value (NPV) remains negative. The break-even selling price of electricity (BESP) was 463 €/MWh, with an NPV of −115 M€. Investment costs dominate lifetime costs, even with potential reductions through industrial integration. Revenues from CO2 utilization and district heat exceed those from the electricity market, highlighting that electricity market revenues alone are insufficient for economic viability. Sensitivity analyses suggest that profitability could be achieved with simultaneous changes in several economic components: 30% decrease in CAPEX and OPEX, increases in electricity market and district heating revenues, a lower electricity tax and discount rate. In conclusion, while CaL TCES has potential for retrofit applications, significant cost reductions are necessary for profitability in renewable energy-based systems like Finland's.</p