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Hydrogen enrichment in methanol SI engine at varying injection timing during compression stroke
Get PDFThis study investigates the effect of hydrogen enrichment in a direct-injected methanol-fuelled SI engine, with combustion and emission performance analysed by varying the methanol injection timing from 150° to 60° CA bTDC. A three-dimensional computational fluid dynamic model of the hydrogen-enriched methanol engine was developed to predict the engine performance, in-cylinder, and emission characteristics. The numerical model was solved using three-dimensional Reynolds-Averaged Navier Stokes, the RNG k-epsilon model for turbulence, the O'Rourke and Amsden sub-model for heat transfer, the extended Zeldovich mechanism for nitric oxide emissions, and the Hiroyasu-NSC model for soot emissions. The results indicated that retarding the injection timing resulted in a decrease in the indicated specific CO and soot emissions along with a rise in the indicated specific NOx emissions. Furthermore, hydrogen enrichment with methanol enhanced the hydroxyl radical concentration, reduced the combustion duration, reduced also the indicated specific CO and soot emissions while increasing the indicated specific NOx emissions. The study indicates that hydrogen enrichment could extend the late injection timing limit of methanol by enhancing fuel-air mixing, which improves and controls the combustion process more effectively.Convergent Science provided CONVERGE licenses and technical support for this work
Roadside Cross-Camera Vehicle Tracking Combining Visual and Spatial-Temporal Information for a Cloud Control System
Get PDFRoadside cameras play a crucial role in road traffic, serving as an indispensable part of integrated vehicle-road-cloud systems due to their extensive visibility and monitoring capabilities. Nevertheless, these cameras face challenges in continuously tracking targets across perception domains. To address the issue of tracking vehicles across nonoverlapping perception domains between cameras, we propose a cross-camera vehicle tracking method within a Vehicle-Road-Cloud system that integrates visual and spatiotemporal information. A Gaussian model with microlevel traffic features is trained using vehicle information obtained through online tracking. Finally, the association of vehicle targets is achieved through the Gaussian model combining time and visual feature information. The experimental results indicate that the proposed system demonstrates excellent performance.10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 52172389);
10.13039/501100003453-Natural Science Foundation of Guangdong Province (Grant Number: 2022A1515012080)
Voltage Profile Improvement in Unbalanced Distribution Networks for Probabilistic Generation and Consumption
Get PDFDue to their technical, economical, and environmental advantages, active distribution networks implement renewable energy resources (RERs) such as photovoltaic (PV) units in distribution networks DNs. However, some drawbacks may arise due to the intermittent nature of RERs, such as voltage fluctuations and increased system losses. This paper presents an optimization problem that is solved by sequential linear programming (SLP) to improve the voltage profile of the unbalanced distribution network. A probabilistic approach was applied to both the load profile and the active power generation of the PV units. SLP is applied to the modified IEEE 34 Bus Test system. The method optimizes the voltage deviations by changing the taps of the voltage regulators and the reactive power injected by the inverters of the PV systems and, in some cases, by switching a shunt capacitor. MATLAB simulations are done at different times of the day with different loads and PV outputs to compare base case and optimal case voltage profiles. The results show better voltage profiles after applying the presented approach.10.13039/501100000308-British Council, This research is funded as a part of the "120N996 Implementing digitalization to improve energy efficiency and renewable energy deployment in Turkish distribution networks" project under the framework of the 2551 Project organized by TUBITAK and the British Council
The Politics of Visibility in Community-based Conservation: Insights from a Village Forest in West Kalimantan, Indonesia
Get PDFData Availability: The data on which this paper was based is not publicly accessible due to privacy restrictions.Conservation organisations play a key role in portraying rural people and places to external audiences, driven by sectoral, political, and technological developments. While aiming to improve social and ecological outcomes, these policies and practices have been criticised for oversimplifying local realities to make them legible, ultimately exacerbating social inequality. However, critiques of legibility often focus on how conservation represents places to outsiders, neglecting the local power dynamics entangled with these representations. This paper shows how conservationist representations are co-produced by and, to varying extents, become visible to local communities. Through ethnographic engagement with the Manjau Village Forest in West Kalimantan, Indonesia, I elaborate on a political understanding of visibility. The politics of visibility is not just an imposition but the product of collaboration and contestation between local and external actors. As such, critiques of visibility can help illustrate the ambivalent relationships that exist between conservation and local communities, clarifying the micro-political risks and opportunities associated with community-based conservation.Arcus Foundation Great Apes Programme (G-PGM-1607–1886) and Brunel University London
A Coupled Molecular-Continuum Framework for Multiscale Simulations of Boiling
Get PDFThe simulation code is publicly available in Github: https://github.com/Crompulence/CPL_APP_OPENFOAM.Abstract Number 26 (https://more.bham.ac.uk/ukhtc-2024/programme/).Boiling is a perfect example of a multiscale process where molecular-level physics giving rise to bubble nucleation interact with larger-scale boundary layers determined by the outer system boundary conditions. We present a novel multiscale simulation method which merges Molecular Dynamics (MD) and Computational Fluid Dynamics (CFD) descriptions into a single modelling framework, where MD resolves the near-wall region where molecular interactions are important, and a CFD solver resolves the bulk flow. We model the progressive heating of a Lennard-Jones fluid via contact with a solid wall until a vapour bubble nucleates in the MD region of the domain and grows by entering in the CFD domain. Our results show that an incompressible CFD flow model based on the Volume Of Fluid (VOF) method with interphase mass transfer calculated via the Hertz-Knudsen-Schrage equation is sufficient to obtain seamless coupling of phase fraction, velocity and temperature fields, with the hybrid MD-CFD framework yielding bubble dynamics closely matching those of MD alone.Embedded CSE programme of the ARCHER2 UK National Supercomputing Service, project ARCHER2-eCSE06-1 "Hybrid Atomistic-Continuum Simulations of Boiling Across Scales"
Sleep Matters in Chronotype and Mental Health Association: Evidence from the UK and Germany
Get PDFData Availability Statement: All data supporting this work will be made freely available via Brunel University London research repository at 10.17633/rd.brunel.25451407.Supplementary Materials: The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/brainsci14101020/s1, Table S1: Correlations (Pearson’s r) between measures of mental health, sleep quality, personality traits and childhood trauma in the UK sample; Table S2: Correlations (Pearson’s r) between measures of mental health, sleep quality, personality traits and childhood trauma in German sample.Background: There is considerable evidence supporting the elevated risk of mental health problems in individuals with evening chronotype relative to those with morning or intermediate chronotypes. Recent data, however, suggest that this risk may be explained, at least partially, by poor sleep quality. Methods: This study aimed to further clarify the roles of chronotype and sleep quality in mental health outcomes (depression, anxiety, stress) in young individuals (18–40 years) living in the UK (n = 185) or Germany (n = 209). Results: Consistent with our recent observations in a comparable North Indian sample, we found that poor quality of sleep had significantly positive associations with adverse mental health outcomes both in the UK and Germany-based samples. Significant associations between evening chronotype and poor mental health were also evident, but these associations were fully mediated by poor quality of sleep in both samples. Conclusions: These observations suggest that efforts to identify sleep disruption in a timely manner and promotion of good sleep may prevent mental health problems, especially in individuals with evening chronotype and other known risks for mental disorders.This research received no external funding
Information exchange and knowledge discovery for additive manufacturing digital thread: a comprehensive literature review
No full textWith the information integration and intelligent embedding of Additive Manufacturing (AM) in intelligent industrial system applications, the information interoperability and knowledge discovery are becoming an infrangible trend that provide efficient data and knowledge-driven approaches for intelligent AM supports. STEP-NC standards in the specific AM digital thread are recognized as a potential means that can be used to explore multi-source data and knowledge analysis to support AM information exchange and knowledge discovery. As a comprehensive review of the related literatures, AM digital thread has deeply been discussed to analyse the information exchange and knowledge discovery for STEP-NC implementations. Furthermore, the STEP-NC for CNC has been reviewed to extend the possibility of STEP-NC for AM with ontology-based knowledge discovery by loads of literatures. In order to deeply explore the integration of STEP-compliant data transfer and knowledge discovery, ontology-based modelling approach and STEP-NC data transfer can be further discussed by combining the application of OntoSTEP-NC to review the literatures of data and knowledge-driven AM supports.National Natural Science Foundation of China, No. 52305551
The actor, the audience and the spy: Tracing actor training methodologies within twentieth century espionage practice and performance
No full textThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThe research builds a genealogy of actor training methodologies as used within espionage
practice, and presents a post-positive historical study with narrative research and
phenomenological framework as its methodology. The thesis examines historical case studies
where espionage and performance overlap. It analyses Second World War training sites created
for the Special Operations Executive (SOE), the personnel, and the training methods used to
prepare agents, and how that training was realised in performance in the field from the 1930s to
the end of the Cold War.
The historical study is preceded by an examination of the 'audience' of undercover events,
analysing the actor-spectator relationship, and theorising how undercover operations can be
considered acts of theatre as well as performance. To address the theoretical intersections
between espionage and theatre, an audience framework entitled Circles of Impact is proposed.
The historical study is organised chronologically and is divided into three parts. The first
surveys the state of theatre in twentieth century Britain and presents an original study of actor
Peter Folliss, who later became an instructor of spies at the SOE's training school at Beaulieu. It
argues that the performances that took place at Beaulieu can be linked to forms of theatre
practice and modes of rehearsal popular at the time. This is followed by a chapter which explores
how this undercover training was realised in performance venues of the Second World War—
both by SOE agents and other actors. The final chapter explores approaches to Cold War
espionage training, the long-lasting influences of Peter Folliss, and legacies linking to
contemporary discussions of actor training
Assessment and improvement of melt quality of recycled secondary A357 alloy by application of the High Shear Melt Conditioning (HSMC) technology
Get PDFData Availability Statement:
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding authors.In addition to impurities in recycled aluminum alloys, non-metallic inclusions are a significant factor that deteriorates the material’s castability and final mechanical properties. This, therefore, restricts the ability to transition from a primary to secondary aluminum alloy. In this study, the cleanliness of the recycled A357 alloy was evaluated through non-metallic inclusions’ characterization, hydrogen content measurement, fluidity test, and casting defects identification. The non-metallic inclusions generated during the recycling process of A357 alloy were collected by the pressurized melt filtration technique. All of the inclusion types collected during filtration were examined and identified by analytical scanning electron microscopy (SEM). Extra additions of up to 2 wt.% swarf in these secondary A357 alloys were designed to simulate highly contaminated alloys. Different to the conventional melt cleaning technologies that mainly focus on complete removal of inclusions, this study developed a novel approach that combines the removal of easily removeable inclusions while preserving well-dispersed inclusions that do not adversely affect the mechanical properties. This study demonstrates that high shear melt conditioning (HSMC) technology can achieve well-dispersed small non-metallic inclusions, low hydrogen content, improved fluidity, and fewer casting defects. As a result, the melt quality of the recycled A357 alloys has achieved a quality comparable to that of primary A357 alloy.This work was supported by the research project Circular Metals (EP/V011804/1) and by a Brunel University London BRIEF award (11937131)
Size matters: measuring the private security industry in the United Kingdom
Get PDFThe private security industry has become a central feature of the plural policing landscape in the United Kingdom. As such, it has received considerable attention in both academic and policy circles. Yet, perhaps surprisingly, there remain notable question marks over its precise size and shape. With this in mind, the article draws upon data from the Security Industry Authority and the Office of National Statistics Business Register and Employment Survey to measure the sector along three key dimensions: the number of private security officers, the number of companies and turnover. This novel methodological approach reveals a complex and contested picture of what the sector looks like at a fundamental level and, at the same time, allows for a reassessment of commonly deployed indicators such as growth rates and the ratio of private security officers to police officers during key time periods such as the Covid-19 pandemic
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