Brunel University Research Archive

    Analytical grid generation and numerical assessment of tip leakage flows in sliding vane rotary machines

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    © 2021 The Author(s). The research presents a new analytical grid generation methodology for computational fluid dynamics studies in positive displacement sliding vane rotary machines based on the user defined nodal displacement approach. This method is more inclusive than state of the art ones since it enables the investigation of a broader range of design configurations, such as single, double and multiple-acting vane machines with non-circular housing, slanted blade and asymmetric blade tip profiles. Node number and radial divisions of blade tip are the parameters that affect most the mesh quality. The method was validated against indicated pressure measurements on a rotary vane expander resulting in a confidence interval within 4.31%. The benchmark analysis showed that the proposed method is as accurate as the manual ANSYS ICEM one but more than 1500 times faster (111s instead of 48h to generate 360 grids). The paper further proposes a novel method to track the leakage flows at the blade tip gaps of vane machines through a post-processing routine in ANSYS CFD-Post based on rotating monitoring planes. The leakage assessment on the vane expander case study showed that a 10 μm gap between blade tip and the 76 mm stator led to a 0.06 unit increase of the expander filling factor.Research Councils UK (RCUK) Centre for Sustainable Energy Use in Food Chains (Grant No. EP/K011820/1); National Science Foundation of China (NSFC, Grant No. 21978227) and the China Scholarship Council (CSC, Grant No. 201906280153)

    A new method for tracking of motor skill learning through practical application of Fitts’ law

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    This article is made available through the Brunel Open Access Publishing Fund.A novel upper limb motor skill measure, task productivity rate (TPR) was developed integrating speed and spatial error, delivered by a practical motor skill rehabilitation task (MSRT). This prototype task involved placement of 5 short pegs horizontally on a spatially configured rail array. The stability of TPR was tested on 18 healthy right-handed adults (10 women, 8 men, median age 29 years) in a prospective single-session quantitative within-subjects study design. Manipulations of movement rate 10% faster and slower relative to normative states did not significantly affect TPR, F(1.387, 25.009) = 2.465, p = .121. A significant linear association between completion time and error was highest during the normative state condition (Pearson's r = .455, p < .05). Findings provided evidence that improvements in TPR over time reflected motor learning with possible changes in coregulation behavior underlying practice under different conditions. These findings extend Fitts’ law theory to tracking of practical motor skill using a dexterity task, which could have potential clinical applications in rehabilitation

    Novel Aninath Computation Detection Algorithm to Identify the UAV Users in 5G Networks

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    Cognitive Radio (CR) Network is a backbone for the 5G cellular Networks and Unmanned Aerial Vehicle (UAV) user identification at low power levels is a biggest task CR. Detection of UAV user is more difficult than the stable or fixed user. In the available literature various authors proposed their research with single detection algorithms low power levels as well as concatenation of two or three detection methods. To estimate the user presence the existing detection methods proposed with covariance based approach at static or predefined threshold power levels. In this paper, the authors proposed a novel Aninath computation detection algorithm to estimate the threshold dynamically with inverse covariance approach to improve the Probability of Detection (P ) and mitigate the Probability of false alarm (P ) and Probability of miss detection (P ) at low power levels. D fa m

    Dynamic exchange capabilities for value co-creation in ecosystems

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    © 2021 Elsevier Ltd. All rights reserved. This is the accepted manuscript version of the article. The final version is available online from Elsevier at: https://doi.org/10.1016/j.jbusres.2021.05.06

    Force-time analysis of the countermovement jump as an indicator of fatigue status in professional academy footballers

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    This thesis was submitted for the award of Mastser of Philosophy and was awarded by Brunel University LondonPurpose: A by-product of the greater financial rewards in elite football is that teams have tended to increase the volume and frequency of their physical training. To reduce the risk of injury and overtraining in players, football coaches need accurate, easy-to-use, and time-efficient monitoring tools for measuring the physical condition of the player. Vertical jump tests are commonly used to determine the player’s neuromuscular fatigue status. However, it is suspected that some skilled players can modify their jumping technique to maintain jump height even when fatigued. Therefore, variables from a jump test other than jump height might be more sensitive indicators of the player’s fatigue state. The aim of this study was to identify the jump metrics that are most sensitive to the delayed neuromuscular fatigue induced by a competitive football match. Methods: This study used a quasi-experiment design with a linear regression analysis of the individual player. Twenty male elite academy footballers performed countermovement jump tests the day before and two days after a competitive match for 20 consecutive weeks during the competition season. After exclusion, data from eight participants were used for the analysis. Seven jump variables related to jump height and jumping technique were selected for analysis. The physical match load variables, very high-speed running and high-intensity decelerations, were plotted separately against the change in each jump variable due to the match. Following an initial visual analysis, a linear regression fit to the data was used to determine the strength of the relationships. Results: Jump height and other countermovement jump variables showed no significant findings when assessing the change from pre- to post-match and there were no universally consistent relationships between the change in a jump variable and the physical match load on a player. Multiple individual differences were observed in the strength of the associations and the direction of these relationships between the jump variables and match load. Conclusion: The absence of statistically significant changes of the countermovement jump variables used in the study suggest that they are not sufficiently sensitive measures to indicate neuromuscular fatigue. However, large individual differences suggest that coaches could utilise countermovement jump monitoring to inform on the altered movement strategy used in the presence of neuromuscular fatigue on an individual level

    Sink or swim: the impact of having a child with Olympic potential on family well-being

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    This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonBehind every young successful athlete, there is always a passionate and supportive social network, most often called ‘family’. Whilst the importance of family on athletes’ development became established, limited effort has been put in exploring the role of sport on the family unit. The aim of this study was to explore the role of elite swimming on the well-being of Cypriot families, which have an adolescent swimmer with Olympic potential. Adopting the Interpretative Phenomenological Analysis approach, this study explored through four rounds of interviews (during the pre-season, beginning and peak of the competition season and off-season) the experiences of the members of four Cypriot swimming families, that took place within a year. The findings provide an in-depth understanding of the phenomenon of family well-being (FWB) in the context of elite swimming in Cyprus, and detail the complex influence that elite sport can have on FWB, through impacting the personal well-being of the individual members and the mutual sense of FWB. It highlights the unique characteristics of each family and discusses how they shape their experiences as well as how specific socio-cultural characteristics of the Cypriot society contribute to similar experiences. This study draws attention on the impact of swimming on individuals’ self-satisfaction and social well-being and highlights the significance of effective communication and members’ ‘togetherness’, as key factors in maintaining FWB during challenging moments in sport. This study offers a framework that can be used in future studies for examining the FWB of other Cypriot families, proposes topics for future studies and suggests potential implications for policy and the practice of sport practitioners, to safeguard FWB.PhD Students Research Grant Programm

    It’s Not About Their Citizenship, it’s About Ours

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    © The Author(s) 2018. Today’s rush to strip terrorist suspects of their citizenship should arouse suspicion. One is easily tempted to think that we are living in extraordinarily dangerous times, which warrant a return to what the US Supreme Court considered to be ‘cruel punishment’ half a century ago. Yet as a matter of statistics, and despite our contrary impressions, violence of all kinds in the world is actually declining. On the other hand, the capacity of law enforcement agencies for surveillance and control, especially in the OECD countries, has increased dramatically, so the return to practices which have long been abandoned is difficult to justify. This is not to say that that citizenship is a sacred cow and any return to abandoned practices is excluded by some historic laws of human progress. But it does follow that the proponents of banishment must provide a more subtle justification than we have seen so far

    Consciously Processing Balance Leads To Distorted Perceptions Of Instability In Older Adults

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    © The Author(s) 2020. Background Persistent dizziness without a clear cause is common in older adults. We explored whether an anxiety-driven preoccupation with consciously processing balance may underpin the distorted perceptions of unsteadiness that characterises ‘unexplained’ dizziness in older adults. Methods We experimentally induced anxiety about losing one’s balance (through a postural threat manipulation) in a cohort of asymptomatic older adults and evaluated associated changes in perceived stability, conscious movement processing and postural control. These outcomes were also assessed when performing a distracting cognitive task designed to prevent anxiety-related conscious movement processing, in addition to during baseline conditions (ground level). Results Despite a lack of increase in postural sway amplitude (p = 0.316), participants reported reductions in perceived stability during postural threat compared to baseline (p < 0.001). A multiple linear regression revealed that anxiety-related conscious movement processing independently predicted perceptions of instability during this condition (p = 0.006). These changes were accompanied by alterations in postural control previously associated with functional dizziness, namely high-frequency postural sway and disrupted interaction between open- and closed-loop postural control (ps < 0.014). While the distraction task successfully reduced conscious processing (p = 0.012), leading to greater perceived stability (p = 0.010), further increases in both postural sway frequency (p = 0.002) and dominance of closed-loop control (p = 0.029) were observed. Conclusion These findings implicate the role of conscious movement processing in the formation of distorted perceptions of unsteadiness, suggesting that such perceptions may be modifiable by reducing an over-reliance on conscious processes to regulate balance

    Impact of inertia distribution on power system stability and operation

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    © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.UK National Gri

    Barriers and Enablers to the Implementation of Intelligent Guidance Systems for Patients in Chinese Tertiary Transfer Hospitals: Usability Evaluation

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    International Collaboration Project for the Building of Double First Class HUS
    Brunel University Research Archive is based in GB