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Advanced MMC-Based Hydrostatic Bearings for Enhanced Linear Motion in Ultraprecision and Micromachining Applications
Get PDFData Availability Statement:
The data are unavailable due to privacy and ethical restrictions.Acknowledgments:
The authors are grateful for continuous support from Brunel University London.This study investigates the impact of material selection on the performance of linear slideways in ultraprecision machines used for freeform surface machining. The primary objective is to address challenges related to load-bearing capacity and limited bandwidth in slow tool servo (STS) techniques. Multi-body dynamic (MBD) simulations are conducted to evaluate the performance of two materials, alloy steel and metal matrix composite (MMC), within the linear slideway system. Key performance parameters, including acceleration, velocity, and displacement, are analyzed to compare the two materials. The findings reveal that MMC outperforms alloy steel in acceleration, velocity, and displacement, demonstrating faster response times and greater linear displacement, which enhances the capabilities of STS-based ultraprecision machining. This study highlights the potential of utilizing lightweight materials, such as MMC, to optimize the performance and efficiency of linear slideways in precision engineering applications.This research received no external funding
Multiple Regression Analysis and Non-Dominated Sorting Genetic Algorithm II Optimization of Machining Carbon-Fiber-Reinforced Polyethylene Terephthalate Glycol Parts Fabricated via Additive Manufacturing Under Dry and Lubricated Conditions
Get PDFData Availability Statement:
Data are contained within the article.The present research deals with the processing of the additively manufactured Carbon-Fiber-Reinforced Polymer (CFRP) under dry and lubricated cutting conditions, focusing on the generated surface roughness. The cutting speed, feed, and depth of cut were selected as the continuous variables. A comparison between the generated surface roughness of the dry and the lubricated cuts revealed that the presence of coolant contributed towards reducing surface roughness by more than 20% in most cases. Next, a regression analysis was performed with the obtained measurements, yielding a robust prediction model, with the determination coefficient R2 being equal to 94.65%. It was determined that feed and the corresponding interactions contributed more than 45% to the modelβs R2, followed by the depth of cut and the machining condition. In addition, the cutting speed was the variable with the least effect on the response. The Non-Dominated Sorting Genetic Algorithm 2 (NSGA-II) was employed to identify the front of optimal solutions that consider both minimizing surface roughness and maximizing Material Removal Rate (MRR). Finally, a set of extra experiments proved the validity of the model by exhibiting relative error values, between the measured and predicted roughness, below 10%.This research received no external funding
Passive thigh heating improves peak force production in younger adults and early isokinetic force production in younger and older adults
No full textData Availability Statement:
The datasets used and/or analysed during the current study are available at Figshare: https://figshare.com/s/b1493067f473fa66a718 (DOI: https://doi.org/10.17633/rd.brunel.28303022).Older adults often suffer from reduced physical capability relative to young adults, in part due to impaired muscle function. This study investigated the ergogenic effects of passive thigh heating on knee extensor torque production in healthy older versus younger adults. Twenty-two younger (YOUNGER; 23 Β± 3 years) and 16 older (OLDER; 68 Β± 8 years) adults completed an experimental visit whereby one thigh was heated via a garment circulating 50Β°C water for 90 min (HEAT) with the contralateral limb unheated (CONT). Four maximal contractions were performed at three isokinetic speeds (slow, 60Β°/s; moderate, 180Β°/s; and fast, 300Β°/s) and an isotonic set (25% maximal voluntary isometric contraction force); contractions were performed on both limbs at baseline and every 30 min thereafter for 120 min, with the final time point used to quantify the retention/decay in response. Vastus lateralis temperature was measured every 30 min, and surface electromyography was implemented throughout. HEAT increased muscle temperature from baseline (31.7 Β± 1.7Β°C) at 30 min (36.5 Β± 1.5Β°C), peaking at 90 min (37.5 Β± 0.7Β°C), all P < 0.05. HEAT increased peak torque during moderate (+11 Β± 12 N m) and fast (+7 Β± 11 N m) contractions in only YOUNGER participants relative to their control leg which remained unchanged (P < 0.05). After 30 min, rate of force development (RFD) in HEAT increased during slow contractions from baseline in both age groups (+229 Β± 210 N m sβ1, P < 0.05) and early force production (EFP) increased in both age groups during slow contractions from 60 min in HEAT (+15 Β± 15 N m, P < 0.05). Peak EMG amplitude was unchanged throughout. Despite a similar increase in the RFD and EFP in both young and older adults, passive thigh heating improves peak knee extensor torque in moderate and fast isokinetic contractions in young adults only.
Highlights
β’ What is the central question of this study?
Can passive thigh heating improve peak torque and early force production in younger and older adults?
β’ What is the main finding and its importance?
Passive thigh heating increased skeletal muscle temperature and peak torque during moderate and fast isokinetic contractions in younger adults and improved early force production during slow contractions in both age groups. Improvements in peak torque decayed after 30 min post-heating whilst improvements in early force production remained. These findings indicate that passive heating could enhance muscle function, especially in older adults where improved early force production may aid mobility and reduce fall risk.None
What nudges you to take a vaccine? Understanding behavioural drivers of COVID-19 vaccinations using large-scale experiments in the G-7 countries
Get PDFData availability statement:
Data is available in Open Science Framework (see: https://doi.org/10.17605/OSF.IO/6MKWG).
Appendix 2 provides readers with a user-friendly codebook to understand how data was collected, cleaned and stored.Supplemental material is available online at: https://www.tandfonline.com/doi/full/10.1080/21642850.2025.2490550# .Introduction:
We present a unique multi-country, two-wave dataset of 42,417 survey responses drawn from nationally representative samples of citizens from the G-7 countries: Canada, France, Germany, Italy, Japan, UK, and USA. This data note outlines the motivation and methodology of the survey instrument and describes the measures contained in the dataset. We highlight areas for future research.
Methods:
We fielded an online survey over two waves (January 27 to February 26 [nβ=β24,303] and wave 2 from March 6 to May 12 [nβ=β18,114]) measuring a range of demographic, social, political, and psychological variables. Samples were nationally representative by age, education, gender, and subnational region. Each wave included of three experiments (one conjoint and two between-subjects) to facilitate randomised evaluation of behavioural health policies promoting the uptake of COVID-19 booster vaccinations.
Results:
The dataset has produced two peer-reviewed publications at the time of writing ([Banerjee, S., John, P., Nyhan, B., Hunter, A., Koenig, R., Lee-Whiting, B., Loewen, P. J., McAndrews, J., & Savani, M. M. (2024). Thinking about default enrollment lowers vaccination intentions and public support in G7 countries. PNAS Nexus, 3(4), pgae093]; [Koenig, R., Savani, M. M., Lee-Whiting, B., McAndrews, J., Banerjee, S., Hunter, A., John, P., Loewen, P. J., & Nyhan, B. (2024). Public support for more stringent vaccine policies increases with vaccine effectiveness. Scientific Reports, 14(1), 1748]). A summary report is posted online (https://www.thebritishacademy.ac.uk/publications/overcoming-barriers-to-vaccination-by-empowering-citizens-to-make-deliberate-choices/). Additional research outputs are currently under preparation.
Discussion:
Our dataset combines observational and experimental data on behavioural health policies, offering numerous insights. First, the dataset's extensive size and geographical diversity enables comparative analysis of public health issues involving social, political, and behavioural factors. Second, the dataset is suited to advanced statistical methods that can explore heterogeneity in the uptake of behavioural health policies, such as vaccine nudges. Third, the timing of the data collection, coinciding with the rise of the Omicron variant, provides valuable insights into why some previously vaccinated individuals might hesitate to receive additional doses, potentially improving our understanding of the COVID-19 pandemic and possible responses to pandemics and other public health emergencies in the future.This work was supported by British Academy
The dynamics of student assessment: how academic motivation, student satisfaction, procrastination and academic resilience shape perceptions of authentic assessments
Get PDFAcknowledgements:
The authors would like to acknowledge Ms C. Fernandes, Ms I. Abdi and Mr M. Faheem for their support with data collection.Authentic assessments provide an important avenue for preparing students with the comprehensive transferrable skills set they will need in pursuit of their future aspirations. This study explored the relationship between academic motivation, student satisfaction, procrastination, academic resilience and studentsβ perceptions of authentic assessments. Regression analyses showed that student satisfaction with assessments, and procrastination significantly predict perceptions of authentic assessments. In contrast, studentsβ academic motivation and academic resilience do not significantly predict perceptions of authentic assessments. In addition, studentβs perceptions of authentic assessment predicted preferences for some types of assessment. The study provides insights into the factors that influence studentsβ perceptions of authentic assessments and suggests areas for improving assessment practices
New WTOD Protocol-Based Fault Detection Filter Design for Interval Type-2 Fuzzy Systems via an Adaptive Differential Evolution Algorithm
Get PDFThis article is concerned with the design problem of an Hβ optimal fault detection (FD) filter for networked interval type-2 (IT2) fuzzy systems that are subjected to stochastic cyberattacks. To effectively reduce the utilization of constrained network resources, a new dynamically adjusted event-triggered weighted try-once-discard (DAET-WTOD) protocol is developed, in which two adaptive rules are constructed based on the measured output and the probability of denial-of-service (DoS) attacks. Furthermore, a fuzzy switched-like FD filter is designed with the purpose of detecting system fault signals, while simultaneously considering the DAET-WTOD protocol and stochastic cyberattacks. Subsequently, by utilizing an imperfect premise matching (IPM) scheme, an opposition-based learning adaptive differential evolution algorithm is proposed to deal with the networked IT2 fuzzy systems. This algorithm is capable of iteratively searching the membership function values of the fuzzy filter in real time, thereby achieving improved Hβ performance. Finally, some simulation results are provided to verify the feasibility and advantages of the proposed Hβ optimal FD technique.10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 62373137)
Framework for food governance in Bangladesh
No full textThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThis thesis investigates the issue of food adulteration in Bangladesh through the lens of
systemic governance, with a focus on its profound socio-economic and public health
ramifications. It critically examines how the historical evolution of governance mechanisms,
fragmented legal frameworks, overlapping institutional mandates, and ineffective
enforcement mechanisms have perpetuated food adulteration. This thesis contends that
addressing this problem necessitates a preventive, governance-oriented strategy rather than
reactionary enforcement approaches. The strengthening and optimisation of existing
regulatory frameworks is key to tackling systemic inefficiencies and reducing consumer
vulnerabilities. Additionally, preventive regulation, multi-stakeholder collaboration, and
gradual improvements are identified as foundational pillars for meaningful progress.
Technological advancements and consumer empowerment are pointed out as important
drivers of long-term regulatory effectiveness.
In emphasising the interconnected roles of the law, government and society, this thesis
integrates socio-legal methodology with doctrinal analysis, historical inquiry, and
comparative insights. This desk-based research critiques the deficiencies of Bangladeshβs
existing food safety governance structures by drawing on international best practices,
particularly those recommended by the Codex Alimentarius and United Nations. It
synthesises legal analysis with policy-driven insights by drawing from case law, legislation,
academic publications, regulatory reports, media sources, and legal commentaries across
various jurisdictions to develop a governance blueprint tailored to Bangladeshβs institutional
and socio-economic context.
This thesis concludes that reorganising internal governance, forming collaborative
partnerships with industry, and actively empowering consumers are the three areas where
the government must take the lead to effectuate change. However, regulatory systems must
be continuously adjusted and improved, as complete eradication of food adulteration
remains an unrealistic goal. A preferable approach could be to adopt modest adjustments
through open communication rather than attempting to achieve perfection all at once. The
safety of Bangladesh's food supply and the overall health of the population depend on this
collaborative and preventative model
A comprehensive safety architecture for humanβrobot collaboration in confined workspaces using improved artificial potential field
No full textSupplementary material is available online at: https://www.cambridge.org/core/journals/robotica/article/comprehensive-safety-architecture-for-humanrobot-collaboration-in-confined-workspaces-using-improved-artificial-potential-field/2B4D5BA2BC36E05E6BA1EE8A254ED3A9#s7 .Acknowledgments:
The authors acknowledge the support of the Robotics and Autonomous Systems group at Brunel University and the Robert Bosch Centre for Cyber Physical Systems at IISc Bangalore. We also thank Mr. Yu She, Mr. Mark Plecnik, Mr. Roel Pieters, Mr. Gianmarco Pisanelli, and Mr. Xuesu Xiao for discussions on robot CAE, HRI dynamics design, and motion planning. We also acknowledge the useful feedback provided by Mr. Gerd Herzinger & Ms. Barbara Schilling (TU Munich) and Ms. Averil Horton (Brunel).Collaborative robotics in manufacturing introduces a new era of seamless humanβrobot collaboration (HRC), enhancing production line efficiency and adaptability. However, guaranteeing safe interaction while maintaining performance objectives presents significant challenges. Integrating safety with optimal robot performance is paramount to minimize task time and ensure its completion. Our work introduces an architecture for safety in confined humanβrobot workspaces by integrating existing safety and productivity methods into a unified framework specifically designed for constrained environments. By employing an improved artificial potential field, we optimize paths based on length and bending energy and compare baseline algorithms like gradient descent algorithm and rapidly exploring random tree (RRT*). We propose an evaluation metric for system performance that objectively maps to the systemβs safety and efficiency in diverse collaborative scenarios. Additionally, the architecture supports multimodal interaction, including gesture-based inputs, for intuitive control and improved operator experience. Safety measures address static and dynamic obstacles using potential fields and safety zones, with a real-time safety evaluation module adjusting trajectories under specified constraints. A performance recovery algorithm facilitates swift resumption of high-speed operations post safety interventions. Validation includes comparing the algorithmic performance through simulations and experiments using the 6-degrees of freedom UR5 robot by universal robots to identify the most suitable algorithm. Results demonstrate an 83.87% improvement in system performance compared to ideal case scenarios, validating the effectiveness of the proposed architecture, evaluation metric, and multimodal interaction in enhancing safety and productivity.This work is supported by the CORE grant CRG2021006698 from the Department of Science and Technology (DST), Government of India, and the Indo-UK Brunel Fellowship Academy (IKB) Grant in digital manufacturing project
Hot Yoga: A Systematic Review of the Physiological, Functional and Psychological Responses and Adaptations
No full textData availability:
All data generated and analysed within this study are included in this published article and/or respective articles included in the systematic review.Background:
Hot yoga is a collective term used to classify any form of yoga undertaken in warm to hot ambient conditions (β₯β25 Β°C). This study systematically reviewed the literature concerning hot yoga, with particular focus on acute responses to a single session and identifying prospective health benefits associated with physiological, functional and psychology adaptations following chronic practice.
Methods:
The review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA), with searches performed across two main databases (PubMed and SCOPUS). Studies were included if they met the Population, Intervention, Comparison, and Outcome (PICO) criteria, were of English language, peer-reviewed, full-text original articles, and using human participants.
Results:
Forty-three studies investigated the effects of hot yoga (both acute and/or chronic), totalling 942 participants (76% female). The most common method of yoga performed in hot conditions was Bikram (74%), followed by generalised hot yoga (19%), Hatha (5%) and then Vinyasa (2%). Typical session duration ranged 20β90 min and occurred within 30β52 Β°C and 20β60% relative humidity. Hot yoga training interventions consisted of 6β36 sessions, that were completed 2β6 times per week, over 1β16 weeks. Acute hot yoga increased body temperature and heart rate, but not the energetic demands when compared to other forms of non-heated yoga. Chronic hot yoga appeared to elicit cardiometabolic (e.g. body composition, lipid profiles and macrovascular function) and functional adaptations applicable for health (e.g., bone mineral density, balance and flexibility) as well as physical performance (e.g., submaximal exercise thresholds). Adaptations appear to occur without negatively impacting kidney function or sleep quality across healthy, sedentary and athletic populations. Hot yoga also presents promising, albeit inconclusive findings concerning the alleviation of psychological and affective disorders, and optimising markers of cognitive function. However, caution is advised as case studies report ill-health following hot yoga practice. Some literature lacks rigorous, high-quality experimental designs and sophisticated measurements that allow for mechanistic investigation.
Conclusion:
Investigations into hot yoga demonstrate intriguing health and functional benefits. However, claims that hot yoga provides greater health benefits than other forms of yoga or traditional exercise are at present unsubstantiated. Studies describing beneficial effects of hot yoga often do not utilise robust experimental designs or methods that facilitate mechanistic insights. Hot yoga warrants further investigation as a tool to improve health and wellbeing. Researchers should consider the highlighted methodological limitations and recommendations to strengthen experimental work within future research.No funding was associated with this research
Shill bidding prevention in decentralized auctions using smart contracts
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The data that has been used is confidential.In online auctions, fraudulent behaviours such as shill bidding pose significant risks. This paper presents a conceptual framework that applies dynamic, behaviour-based penalties to deter auction fraud using blockchain smart contracts. Unlike traditional post-auction detection methods, this approach prevents manipulation in real-time by introducing an economic disincentive system where penalty severity scales with suspicious bidding patterns. The framework employs the proposed Bid Shill Score (BSS) to evaluate nine distinct bidding behaviours, dynamically adjusting the penalty fees to make fraudulent activity financially unaffordable while providing fair competition.
The system is implemented within a decentralized English auction on the Ethereum blockchain, demonstrating how smart contracts enforce transparent auction rules without trusted intermediaries. Simulations confirm the effectiveness of the proposed model: the dynamic penalty mechanism reduces the profitability of shill bidding while keeping penalties low for honest bidders. Performance evaluation shows that the system introduces only moderate gas and latency overhead, keeping transaction costs and response times within practical bounds for real-world use. The approach provides a practical method for behaviour-based fraud prevention in decentralised systems where trust cannot be assumed.Mohamed Abdelhai Bouaicha is currently the beneficiary of a Ph.D. research grant partially funded by the Italian Ministerial Decree No. 352/2022 β PNRR, Mission 4, Component 2, βFrom Research to Enterpriseβ β Investment 3.3. βIntroduction of innovative doctoral programs that respond to the needs of enterprises and promote the recruitment of researchers from enterprisesβ β an innovative doctoral scholarship with an industrial focus.
This research was also partially funded by the Apulian Italian Region within the project βINVISIBLE BUSINESS - EXPONENTIAL TECHNOLOGIES FOR INVISIBLE BUSINESSESβ under the Regional Operational Programme βP.O. PUGLIA FESR 2014β2020 β Asse I β Obiettivi specifici 1a Azione 1.1 Sub-Azione 1.1.b β Regolamento Regionale del 30 settembre 2014, n. 17 e s.m.i. β Titolo II β Capo 2 β Art. 26 β PROGRAMMI INTEGRATI DI AGEVOLAZIONE β PIA MEDIE IMPRESEβ, funded through the βAtto Dirigenzialeβ n.686 β 20/09/2021
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