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Thermodynamic evaluation of shell and tube heat exchanger through advanced exergy analysis
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No data was used for the research described in the article.Shell and tube heat exchanger is a pivotal equipment used in industries for heat transfer. Any effort to minimize the irreversibility in the heat exchanger will enhance the performance and leads to energy optimization and cost savings. In the current study, a water to water, segmental baffled shell and tube heat exchanger was considered for an investigation and designed using the Kern method. Exergy analysis and advanced exergy analysis was carried out to understand the performance of the heat exchanger and to determine the possibility of reducing irreversibilities. The results of the exergy analysis showed that the system has 684.6 kW of exergy destruction. Advanced exergy analysis was carried out through endogenous and exogenous modes and subsequently performed for avoidable and unavoidable components. Majority of the exergy destruction in the heat exchanger is avoidable. The results showed that 97.5 % of the total exergy destruction is of endogenous avoidable type. The system can be improved by changing the system configuration, design variables, mass flow rates, materials, and many other parameters. Subsequently, the exergy destruction in the pumps is unavoidable and no further design improvements are required.The work is done as part of the collaboration between Pandit Deendayal Energy University, India and the Heat Pipe and Thermal Management Research Group (HPTM) at Brunel University London, UK. The HPTM's part was partially funded from the European Union’s H2020 programme iWAYS under grant agreement numbers 958274)
Intersectional solidarities and inter-individual affinities: Enactments of equity and privilege through doctoral supervision relationships
Get PDFThis article draws on a research project about the transition from PhD student to academic (British Academy-Leverhulme research grant, 2020–2022). Semi-structured interviews were conducted with 26 recent PhD graduates and six PhD supervisors. Transcripts were subjected to a thematic analysis. On a theoretical level, the article is informed by Bourdieu’s concepts of cultural and social capital, with a focus on the differential cultural and social capital available to participants through their doctoral and postdoctoral journeys. On an empirical level, we focus on two interviews with recent PhD graduates to explore how equity and privilege play out in intersectional ways in the post/doctoral journey and are mediated by doctoral supervisors as gatekeepers. In particular, we identify two discourses of supervisory support which emerged in the participants’ narratives: intersectional solidarities and inter-individual affinities, and reflect on their implications for equity.British Academy as part of the 2020 British Academy-Leverhulme Small Research Grants programme
Wavy-attention network for real-time cyber-attack detection in a small modular pressurized water reactor digital control system
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The link to data and code is embedded in the paper (available online at: https://github.com/abiodun-ayodeji/Wavy-attention-network-for-cybersecurity)..Corrigendum: The authors regret, that the affiliation for Abiodun Ayodeji was incorrectly listed in the original publication. The correct affiliation should be updated as above.
The research presented in this paper was conducted while Abiodun Ayodeji was affiliated with the Nuclear Futures Institute at Bangor University and is not related to their current work at the Brunel Innovation Centre, Brunel University London.
This corrigendum does not affect the scientific content or conclusions of the article in any way.
The authors would like to apologise for any inconvenience caused.Global interest in advanced reactors has been reignited by recent investments in small modular reactors and micro-reactor design. The use of digital devices is essential for meeting the size and modularity requirements of small modular reactor controls. By fully digitizing the small modular reactor control systems, critical information can be obtained to optimize control, reduce costs, and extend the reactor’s lifetime. However, the potential for cyber-attacks on digital devices leaves digital control systems vulnerable. To address this risk, this study presents a novel wavy-attention network for sensor attack detection in nuclear plants. The wavy-attention network comprises stacks of batch-normalized, dilated, one-dimensional convolution neural networks, and sequential self-attention modules, superior to conventional single-layer networks on sequence classification tasks. To evaluate the proposed wavy-attention network architecture, the International Atomic Energy Agency’s Asherah Nuclear Simulator and a false data injection toolbox found in the literature, both implemented in MATLAB/SIMULINK, are utilized. This approach leverages changes in process measurements to identify and classify cyber-attacks on priority signals using the proposed wavy-attention network. Three false data injection attacks are simulated on the simulator’s pressure, temperature, and level sensors to obtain representative process measurements. The wavy-attention network is trained and validated with normal and compromised process variables obtained from the simulator. The performance of the wavy-attention network to discriminate between the reactor states using the test set shows 99% accuracy, as opposed to other baseline models such as vanilla convolution neural networks, long short-term memory networks, and bi-directional long short-term memory networks with 90%, 77%, and 91% accuracy, respectively. An ablation study is also conducted to test the contribution of each component of the proposed architecture. The theoretical framework of the proposed wavy-attention network and its implementation for nuclear reactor digital sensor attack detection are discussed in this paper.This work is partially supported by the High Value Manufacturing Catapult through NIN2394-FY2023 Developing Cyber Security Capability; by the CHIST-ERA funded TROCI Project (CHIST-ERA-22-SPiDDS-07) through the Engineering and Physical Sciences Research Council (EPSRC) under grant EP/Y036344/1; and by the Sêr Cymru II 80761-BU-103 project by the Welsh European Funding Office under the European Regional Development Fund
Global, regional, and national burden of mortality associated with cold spells during 2000–19: a three-stage modelling study
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All used data were obtained from the Multi-Country Multi-City (MCC) Collaborative Research Network (https://mccstudy.lshtm.ac.uk/) under a data sharing agreement and cannot be made publicly available. Researchers can refer to MCC participants, who are listed as coauthors of our study, for information on accessing the data for each country.Supplementary Material is available online at: https://www.sciencedirect.com/science/article/pii/S2542519623002772#sec1 .Background:
Exposure to cold spells is associated with mortality. However, little is known about the global mortality burden of cold spells.
Methods:
A three-stage meta-analytical method was used to estimate the global mortality burden associated with cold spells by means of a time series dataset of 1960 locations across 59 countries (or regions). First, we fitted the location-specific, cold spell-related mortality associations using a quasi-Poisson regression with a distributed lag non-linear model with a lag period of up to 21 days. Second, we built a multivariate meta-regression model between location-specific associations and seven predictors. Finally, we predicted the global grid-specific cold spell-related mortality associations during 2000–19 using the fitted meta-regression model and the yearly grid-specific meta-predictors. We calculated the annual excess deaths, excess death ratio (excess deaths per 1000 deaths), and excess death rate (excess deaths per 100 000 population) due to cold spells for each grid across the world.
Findings:
Globally, 205 932 (95% empirical CI [eCI] 162 692–250 337) excess deaths, representing 3·81 (95% eCI 2·93–4·71) excess deaths per 1000 deaths (excess death ratio), and 3·03 (2·33–3·75) excess deaths per 100 000 population (excess death rate) were associated with cold spells per year between 2000 and 2019. The annual average global excess death ratio in 2016–19 increased by 0·12 percentage points and the excess death rate in 2016–19 increased by 0·18 percentage points, compared with those in 2000–03. The mortality burden varied geographically. The excess death ratio and rate were highest in Europe, whereas these indicators were lowest in Africa. Temperate climates had higher excess death ratio and rate associated with cold spells than other climate zones.
Interpretation:
Cold spells are associated with substantial mortality burden around the world with geographically varying patterns. Although the number of cold spells has on average been decreasing since year 2000, the public health threat of cold spells remains substantial. The findings indicate an urgency of taking local and regional measures to protect the public from the mortality burdens of cold spells.Australian Research Council, Australian National Health and Medical Research Council, EU's Horizon 2020 Project Exhaustion. This study was supported by the Australian Research Council (DP210102076), the Australian National Health and Medical Research Council (APP2000581) and the EU's Horizon 2020 Project Exhaustion (Grant ID: 820655). YGa and WH were supported by the China Scholarship Council (number 202008110182 and number 202006380055). YGu was supported by the Leader Fellowship (number APP2008813) of the Australian National Health and Medical Research Council. QZ was supported by the Natural Science Foundation of Shandong Province in China (grant ZR2021QH318) and the Shandong Excellent Young Scientists Fund Program (Overseas) (grant 2022HWYQ-055). AG was supported by the European Union's Horizon 2020 Project Exhaustion (Grant ID: 820655). JK and AU were supported by the Czech Science Foundation (project 22-24920S). VH was supported by the European Union's Horizon 2020 Research and Innovation Programme (Marie Skłodowska-Curie Grant Agreement Number 101032087), and SL was supported by an Emerging Leader Fellowship of the Australian National Health and Medical Research Council (number APP2009866)
An assessment of current hydrogen supply chains in the Gulf Cooperation Council (GCC)
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Data will be made available on request.The Gulf Cooperation Council (GCC), comprising: Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Oman, and Bahrain, is home to an abundant number of resources, including natural gas and solar and wind energy (renewables). Because of this, the region is favourably positioned to become a significant player in both blue and green hydrogen production and their export. Current dependence on fossil fuels and ambitious national targets for decarbonisation have led the region and world to research the feasibility of switching to a hydrogen economy. This literature review critically examines the current advantages and strategies adopted by the GCC to expedite the implementation of hydrogen supply chains, as well as investigation into the methodologies employed in current research for the modelling and optimisation of hydrogen supply chains. Insight into these endeavours is critical for stakeholders to assess the inherent challenges and opportunities in establishing a sustainable hydrogen economy. Despite a substantial global effort, establishing a solid hydrogen supply chain presently faces various obstacles, including the costs of clean hydrogen production. Scaling-up storage and transport methods is an issue that affects all types of hydrogen, including carbon-intensive (grey) hydrogen. However, the current costs of green hydrogen production, mostly via the process of electrolysis, is a major obstacle hindering the widescale deployment of clean hydrogen. Research in this literature review found that compressed gas and cryogenic liquid options have the highest storage capacities for hydrogen of 39.2 and 70.9 kg/m3, respectively. Meanwhile, for hydrogen transportation, pipelines and cryogenic tankers are the most conventional and efficient options, with an efficiency of over 99 %. Cryogenic ships to carry liquid hydrogen also show potential due to their large storage capacities of 10,000 tonnes per shipment, However, costs per vessel are currently still very expensive, ranging between 620 million
The Invisible Owners: On the rise of asset management
No full textTo what extent is the fate of the planet in the hands of asset managers
A comparative examination of corporate criminal liability: Towards the expansion of corporate criminal liability in the international law
No full textThis thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonAs an introduction to the thesis, I use the conceptual framework of the corporate moral agent as a device designed to shed light upon a number of difficulties which beset the criminal law in the field of commerce. Whereas corporations can be accused of offences which require a mens rea component, the courts and scholars have endured a protracted struggle to establish the location of a mens rea inside the company structure. I expand upon the collectivist approach to mens rea to illuminate a form of corporate structural recklessness known as corporate mens rea. Insufficient thought has been given, and academic rigour has been devoted to the degree to which excuses may be considered valid in the corporation sphere. I portray the manner in which, in very particular circumstances, a company could legitimately proffer a reason for duress despite the fact that the very concept invokes the idea of the accused being prompted by the emotion of fear.
So far, the cross-border courts have not yet ascertained a workable means of reining in multinational corporations (MNCs) and ensuring compliance with trans-international human rights criteria. The matter causes difficulties for nations which are significantly in need of MNC investments to further their economic progress. African countries, for example, are notorious for competing for influxes of funds by reducing the strictness of their laws for the benefit of MNCs. This gives the latter the leeway to pursue breaches of human rights and engage in international offences. This research aims to improve the situation by scrutinising the way in which MNCs can be held criminally liable on a global basis if they run substantially foul of human rights legislation. During the course of the last century, two critical events in international jurisprudence demonstrated the possibility of keeping multinational concerns criminally accountable. These were: the Nuremberg Trials, in the wake of the Second World War, which posited corporate criminal liability, and the consultations prior to the founding of the International Criminal Court (ICC) in the Nineties, during which the addition of criminal liability to the corporate sphere was proposed. Many countries bestow such liability at the state stage.
In many cases, this emanates from a determination of criminal liability on the part of an individual company representative. Irrespective of this, the United Kingdom and Australia have effectively delineated how a corporation may be found criminally liable without any requirement to base any such liability on an official. These measures make clear the feasibility of taking MNCs criminally liable by means of either a derivative or non-derivative mechanism. Indeed, the treatise at hand suggests that MNCs can be found criminally liable for aiding and abetting international offences in accordance with Article 25(3)(c) in the ICC Statute. In pursuit of this, the research utilises the concepts of non-derivative criminal liability founded in the United Kingdom and Australia. It cultivates a theory of corporate criminal liability for aiding and abetting cross-border offences that encompass these tenets and proposes how this could work in the international jurisdiction of the ICC. This hypothesis reflects the foundation of an innovative approach by the ICC in what we say now is the determination of corporate criminal liability for aiding and abetting
“Keeping the Queen’s Peace”: A Sociomaterial Study of Police and Guns in a “Mangle of Risk”
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Data will be made available on request.This sociomaterial study analyzes the ways that material agency plays a key role in the organizing dynamics of risky work through a study of the carrying and use of handguns by U.S. and U.K. police officers. Qualitative data (interviews and focus groups) were collected over a three-year period with police (N = 61) in New York, where officers routinely carry guns, and in London, where they typically do not. Police unanimously describe the agentic role non-human artefacts like guns play in: a) framing their cognitive processes, b) influencing their behaviour and decision-making processes, and c) impacting individuals around them. Expanding Pickering's theorization of a mangle of practice, we inductively develop a mangle of risk to explain how human and non-human agency become entangled in risky work contexts, where danger is real and time pressure is high. Understanding these dynamics requires analysis of both frontline police narratives and the prescribed organizational policies, procedures, and routines intended to contain risky situations. Findings reveal that the tools provided to police to do their job both frame and constrain operational capabilities, potentially escalating danger for police, suspects, and the community in a mangle of risk
Prevalence of hypertension in employees of oil and gas companies: A sex-stratified analysis from Northwest China
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The data supporting this study's findings are available from Administrative Affairs Centre, Changqing Oil Field Filiale, Xi'an, Shaanxi Province, China. However, restrictions apply to the availability of these data, which were used under license for the current study, and are not publicly available. Data are, however, available from the authors upon reasonable request and with permission of Administrative Affairs Centre, Changqing Oil Field Filiale, Xi'an, Shaanxi Province, China.Background: This study aims to determine whether employees of an oil and gas company in Shaanxi, China, are associated with a higher prevalence of hypertension compared to the general population's age and geographical region.
Methods: Cross-sectional study is used. Participants with hypertension who fulfilled at least one of the criteria: (1) systolic blood pressure ≥140 mm Hg; (2) diastolic blood pressure ≥90 mm Hg; (3) self-reported use of antihypertensive medication in the past two weeks; or (4) self-reported history of hypertension.
Result: Compared to the general population, the employees were young, with a higher proportion of men having a higher body mass index and were more likely to be alcoholics and smokers. Before propensity score matching, the prevalence of hypertension was slightly lower in the employees compared to that of the general population. After matching, overall, the employees were more likely to have hypertension compared to the general population. Gender-based subgroup analysis showed that male employees had a higher prevalence of hypertension, while the female employees had a lower prevalence of hypertension compared to the general population.
Conclusion: The research results show that compared with the general population, male oilfield employees are more prone to hypertension. This finding potentially has implications for the subsequent designating of preventative modalities. Specifically, policies concerning the prevention, treatment, and control of hypertension, as well as health management in the oil and gas companies should be formulated differently for male and female workers and be more focused on males and front-line workers.National Natural Science Foundations (No. 82204151, No. 82304238)
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