30793 research outputs found
Sort by
The Path to Carbon Capture Technology Adoption—A System Dynamics Approach
Get PDFData Availability Statement:
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.A system dynamics approach is described to explore the path of Carbon Capture diffusion. The proposed model, in principle, follows the Bass diffusion of innovation theory and includes all major influencing factors. The primary contribution of this paper is the modification of Bass’s model to reflect parameters affecting the adoption of Carbon capture and storage technology. Consequently, it differs from other extensions to Bass’s model. The underpinning of this work is the system dynamics (SD) approach, which can open a pathway for further research into CCS acceptance. The proposed model’s behaviour is illustrated for various transition pathways of the technology, for different regimes. By modifying the proposed model, the paper also allows consideration of various capturing technologies on their merit. The proposed framework enables the examination of the impact of intervention policies on the adoption of CCS by individual investors. The purpose is to identify the parameters of these policies to support the under-resourced CCS technology and reduce the need for government participation. It is worth noting that the SD is primarily a descriptive method used for scenario analysis to illustrate what the future would look like.This research received no external funding
Natural Frequency and Damping Characterisation of Aerospace Grade Composite Plates
Get PDFData Availability Statement:
The data presented in this study are available upon request from the corresponding author.The natural frequencies and damping characterisation of a new aerospace grade composite material were investigated using a modified impulse method combined with the half power bandwidth method, which is applicable to the structures with a low damping. The composite material of interest was unidirectional carbon fibre reinforced plastic. The tests were carried out with three identical square 4.6 mm thick plates consisting of 24 plies. The composite plates were clamped along one edge in a SignalForce shaker, which applied a sinusoidal signal generated by the signal conditioner exiting the bending modes of the plates. Laser vibrometer measurements were taken at three points on the free end so that different vibrational modes could be obtained: one measurement was taken on the longitudinal symmetry plane with the other two 35 mm on either side of the symmetry plane. The acceleration of the clamp was also recorded and integrated twice to calculate its displacement, which was then subtracted from the free end displacement. Two material orientations were tested, and the first four natural frequencies were obtained in the test. Damping was determined by the half-power bandwidth method. A linear relationship between the loss factors and frequency was observed for the first two modes but not for the other two modes, which may be related to the coupling of the modes of the plate and the shaker. The experiment was also modelled by using the Finite Element Method (FEM) and implicit solver of LS Dyna, where the simulation results for the first two modes were within 15% of the experimental results. The novelty of this paper lies in the presentation of new experimental data for the natural frequencies and damping coefficients of a newly developed composite material intended for the vibration analysis of rotating components.This research received no external funding
Process-Driven Structural and Property Evolution in Laser Powder Bed Fusion of a Newly Developed AISI 316L Stainless Steel
Get PDFData Availability Statement:
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.The lack of new materials with desired processability and functional characteristics remains a challenge for metal additive manufacturing (AM). Therefore, in this work, a new promising AISI 316L-based alloy with better performance compared to the commercially available one is developed via the laser powder bed fusion (L-PBF) process. Moreover, establishing process–structure–properties linkages is a critical point that should be evaluated carefully before adding newly developed alloys into the AM market. Hence, the current study investigates the influences of various process parameters on the as-built quality and microstructure of the newly developed alloy. The results revealed that increasing laser energy density led to reduced porosity and surface roughness, likely due to enhanced melting and solidification. Microstructural analysis revealed a uniform distribution of copper within the austenite phase without forming any agglomeration or secondary phases. Electron backscatter diffraction analysis indicated a strong texture along the build direction with a gradual increase in Goss texture at higher energy densities. Grain boundary regions exhibited higher local misorientation and dislocation density. These findings suggest that changing the process parameters of the L-PBF process is a promising method for developing tailored microstructures and chemical compositions of commercially available AISI 316L stainless steel.This research received no external funding
Mixed-methods study exploring medium to longer-term outcomes following selective dorsal rhizotomy in ambulatory children with cerebral palsy at a tertiary hospital in the UK: MOSAiC study protocol
Get PDFSupplemental material is available online at https://bmjopen.bmj.com/content/bmjopen/15/12/e108558/DC1/embed/inline-supplementary-material-1.pdf?download=true and https://bmjopen.bmj.com/content/bmjopen/15/12/e108558/DC2/embed/inline-supplementary-material-2.pdf?download=true .Introduction: Selective dorsal rhizotomy (SDR) is one of the treatment options available for spasticity management in ambulatory children and young people with cerebral palsy (CYPwCP). Although improvements in gross motor function one to two years after surgery have been established, evidence of longer-term benefit requires further investigation. Given the irreversible nature of SDR and the increased rehabilitation commitments required from families and clinicians, providing evidence of longer-term benefits is essential to support their decision-making. This study aims to investigate medium (3–5 years) and long-term (6–10 years) SDR outcomes in ambulatory children with CP and how SDR affects families’ lives over time.
Methods and analysis: This is a convergent parallel mixed-methods study using the International Classification of Functioning, Disability and Health as a theoretical framework. The study aims to recruit 90 CYPwCP participants, who had SDR at a tertiary hospital in the UK when aged between 3 and 14 years. Participants (parents and CYPwCP) will be invited to complete an online survey and attend the hospital for one follow-up visit 3 or more years after SDR. Comparisons will be made with existing data on objective measures and parent-reported outcomes collected in clinical practice at baseline, 6, 12 and 24 months to understand the trajectory of changes. Semistructured interviews will be conducted with 18–20 parents/carers and 25–30 CYPwCP to understand their perspectives on the outcomes of SDR compared with their prior expectations. The Framework Method will be used to analyse qualitative data both inductively and deductively. Qualitative and quantitative study data will be integrated using joint displays.
Ethics and dissemination: Ethical approval has been obtained through the Coventry and Warwick Research and Ethics Committee (24/WM/0078). Findings will be shared through international conferences, peer-reviewed journals, social media and dissemination events for families and CYP.
Trial registration number: NCT06518889.DC is funded by the NIHR Doctoral Clinical Academic Research Fellowship (NIHR 302916) Health Education England (HEE)/NIHR for this research project. HG is funded by an NIHR Advanced Fellowship (NIHR 303636) Health Education England (HEE)/NIHR
Trade Unions and Informal Power Dynamics: Exploring Tout Operations in Nigeria's Metropolitan Transport System
Get PDFPurpose: This study examines the intersection of trade unions and informal tout operations in
the transport systems of 5 metropolitan cities in Nigeria. It explores the dynamics of power,
control, and influence within the transport sector, highlighting how trade unions interact with
informal actors and the implications for urban mobility and governance.
Design/Methodology/Approach: The research employs a qualitative methodology,
incorporating in-depth interviews, participant observations, and document analysis. Key
stakeholders, including union leaders, transport operators, and touts, were interviewed across
multiple metropolitan areas in Nigeria. The study also draws on policy documents and
secondary data to contextualise the findings within broader socio-political frameworks.
Anticipated Findings: The study anticipates uncovering a complex relationship between trade
unions and touts, where both formal and informal structures coexist and occasionally conflict.
It is expected that trade unions rely on touts to enforce rules, maintain order, and generate
revenue, while touts operate as informal power brokers. This relationship, while functional in
some contexts, contributes to inefficiencies, conflicts, and corruption within the transport
system.
Practical Implications: The findings will provide valuable insights for policymakers,
transport regulators, and urban planners in Nigeria. Understanding the interactions between
formal and informal actors can inform strategies to improve governance in the transport sector,
reduce exploitation, and enhance service delivery. The study also offers practical
recommendations for harmonising the roles of trade unions and informal operators to create a
more efficient and equitable system.
Originality/Value: This study contributes to the literature on urban transport governance by
shedding light on the underexplored relationship between trade unions and informal tout
operations in Nigeria. It provides a unique perspective on how informal practices shape formal
systems in a developing country context, offering new insights into urban mobility challenges
in the Global South
Loss evaluation and performance modelling of power electronics for fault management and renewable energy integration
Get PDFData availability statement:
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.Generative AI statement:
The authors declare that no Generative AI was used in the creation of this manuscript.This work presents the performance and efficiency analysis of solid-state power electronic devices in two complementary applications: fault current limiting and renewable energy integration. A solid-state Fault Current Limiting and Interrupting Device (FCLID) based on a Switched Capacitor (SC) circuit is evaluated for its ability to perform power factor correction and voltage regulation during normal grid operation. Particular focus is given to switching losses in semiconductors, analysed using the PSIM Thermal Module. The 90° phase shift observed between current and voltage in SC circuits is contrasted with in-phase behaviour in DC-DC converters. IGBT losses are calculated and shown to closely align with simulation and literature-based estimates. The second part of the study investigates a grid-connected photovoltaic (PV) system with power smoothing capability, designed to mitigate output fluctuations due to environmental variability. A bidirectional DC-DC converter and a partially controlled lithium-ion battery are used to reduce voltage flicker and improve grid stability. PSIM simulations incorporate MPPT control, inverter modelling, and real-world component characteristics. Losses are primarily concentrated in switching transistors, diodes, and inductors. Across both systems, efficiency is critically evaluated as a primary determinant of performance and economic viability. The simulated and analytical loss results show agreement within 1%, thereby validating the modelling approach. The findings indicate that lower switching frequencies consistently yield overall system efficiencies above 96%, irrespective of whether MOSFETs or IGBTs are employed. However, the study also reveals that reverse recovery losses become negligible compared to conduction losses only at low switching frequencies (<10 kHz) and low current slew rates (di/dt < 100 A/µs). Finally, the analysis demonstrates that practical implementation factors can increase total power losses by up to 21%.The authors declare that no financial support was received for the research and/or publication of this article
Plasma biomarkers in neuropsychiatric syndromes: A narrative review
Get PDFAcknowledgements:
This article was facilitated by the Alzheimer’s Association International Society to Advance Alzheimer’s Research and Treatment (ISTAART) through the Biofluid Based Biomarkers in Neuropsychiatric Syndromes work group, a joint work group of the Biofluid Based Biomarkers Professional Interest Area and the Neuropsychiatric Syndromes Professional Interest Area.Neuropsychiatric symptoms (NPS) are common features of neurodegenerative disease (NDD) but are relatively understudied compared to cognition, especially regarding biomarkers. Further, emerging evidence describes the utility of systematic assessment of NPS across the cognitive continuum, even in advance of dementia. In this narrative review, we discuss the role of plasma biomarkers in relation to NPS across the cognitive continuum of unimpaired, subjective cognitive decline, mild cognitive impairment, and dementia. While Alzheimer's disease is the primary focus, vascular, Lewy body, and frontotemporal dementia etiologies are also discussed. Literature searches included NPS and dementia-related search terms with additional literature identified based on the author group's subject area expertise. We found that plasma biomarkers are a burgeoning field, and scalability and accessibility make them well-suited for the study of NPS across the disease continuum. In early-stage NDD, diagnostic biomarkers are best suited for discriminating NDD-related NPS from non-NDD psychiatric syndromes and/or NPS due to other causes. In those with dementia, monitoring and prognostic biomarkers may enable the assessment of treatment response or help predict the risk of worsening symptoms. We conclude that plasma amyloid-β and tau show great promise in assessing NPS, especially during early-stage disease, but inflammatory and genetic biomarkers may also play a role across the disease course. Systematic research is required, keeping in mind the ethical considerations of knowing biomarker status in early-stage disease.This work was supported by the Cumming School of Medicine, University of Calgary
Circular Pathways in Construction: Environmental Life Cycle Assessment of Bio-based Fiber Reinforced Building Component
Get PDFData availability statement:
The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding authors.Supplementary material:
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/frsus.2025.1716779/full#supplementary-materialGenerative AI statement:
The author(s) declared that generative AI was not used in the creation of this manuscript.The construction sector is one of the most significant contributors to global environmental impacts, particularly due to its high material and energy demands. Developing sustainable alternatives to conventional building materials is, therefore, a critical step toward reducing the environmental impact of this sector. The integration of recycled bio-based fibers with traditional reinforcement is proposed as an alternative solution to mitigate environmental impacts. This study evaluated the environmental benefits of replacing traditional steel reinforcement with recycled bio-based hemp and bamboo fibers in a reinforced concrete beam using the Life Cycle Assessment (LCA) methodology, excluding the evaluation of the mechanical performance of the replacement materials from its scope. The results show that, overall, replacing steel has significant benefits for several impact categories even at low replacement rates for the reinforced concrete beam. For instance, in terms of global warming potential (GW), the emissions decrease from 362 kg CO2 eq for beam for the steel-reinforced concrete to 324 kg CO2 eq for beam for 30% steel replacement with recycled hemp and 312 kg CO2 eq for beam for 30% steel replacement with recycled bamboo fiber. Therefore, the GW emissions decrease by around 14% for the reinforced concrete beam. This study contributes to the scientific literature by providing concrete data on the benefits of using bio-based recycled fibers even at low replacement rates. This research suggests that utilizing recycled bio-based materials could be a practical approach to enhancing the sustainability of construction materials from a circular economy perspective.The author(s) declared that financial support was received for this work and/or its publication. This research received no external funding
Dynamic Event-Driven State Estimation for Complex Networks via Partial Nodes’ Sampled Outputs: An Encoding-Decoding Scheme
Get PDFIn this article, the encoding-decoding-based state estimation problem is investigated for a class of continuous-time nonlinear complex networks (CNs) subject to communication bandwidth constraints. Based on the sampled outputs from a subset of network nodes, a novel dynamic event-driven encoding mechanism is integrated into the design of state estimator, where a time-varying auxiliary parameter is utilized to modulate the triggering condition in a dynamical fashion, enabling the event detector to decide whether the data packet should be released at the periodic sampling instants. Specifically, when the dynamic triggering condition is satisfied, the data are first encoded into a codeword and subsequently transmitted to the estimator through a digital communication channel. The Zeno behavior can be naturally prevented due to the periodic feature of the proposed event detector. By leveraging the Lyapunov theory and the matrix inequality techniques, sufficient conditions are established to ensure the exponential stability of the estimation error system. In addition, a convex optimization approach is employed to design the estimator gain with the goal of maximizing the allowable bound of the sampling intervals. Finally, an illustrative example and a practical example involving a three-area power system are provided to showcase the effectiveness of the proposed state estimation method.10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 62173292, 62376242, 62103359 and 62506326);
10.13039/501100001809-Postdoctoral Fellowship Program of China Postdoctoral Science Foundation (CPSF) of China (Grant Number: GZC20232210);
Key Laboratory of Yangzhou of China (Grant Number: YZ2024245)
Data sources:
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇