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Novel Insights into the Palaeomagnetism of Serpentinized Peridotites from the Troodos and Oman Ophiolites
Get PDFLarge volumes of mantle peridotite are exposed at the Earth’s surface in ophiolites, becoming vulnerable to the concurrent chemical alteration processes of serpentinization and carbonation. Serpentinization frequently results in the production of secondary magnetite that can record the direction of the Earth’s magnetic field at the time of its formation, allowing palaeomagnetism to be used as a tool to investigate this process. Many ophiolites also experienced large-scale tectonic rotations during their evolution. In some cases, the timing of these rotations is well-documented palaeomagnetically, potentially allowing the timing of different phases of serpentinization to be constrained if the magnetization directions of secondary magnetite assemblages can be determined and compared to known rotation histories. This research represents the first attempt to combine paleomagnetic and rock magnetic analyses of serpentinized mantle peridotites with state-of-the-art Quantum Diamond Microscopy (QDM), a recently developed analytical tool that allows two-dimensional images of the magnetic fields in a sample arising from distributions of magnetic sources.Two ophiolites are the focus of this thesis. The Late Cretaceous Troodos ophiolite of Cyprus that underwent a ~90° anticlockwise tectonic rotation that began shortly after it formed by seafloor spreading. The timing of this rotation is well-constrained by palaeomagnetic analysis of the sedimentary rocks that were deposited continuously while the underlying oceanic crust rotated. In this context, different magnetization directions would be expected to be carried by magnetite assemblages produced by serpentinization during: (i) early exposure on the seafloor or deep fluid circulation during Late Cretaceous seafloor spreading; (ii) subsequent progressive tectonic rotation; and (iii) Plio-Quaternary to Recent tectonic uplift and/or reaction with modern meteoric water. The Late Cretaceous Samail/Semail ophiolite in Oman and the UAE (hereafter referred to as the Oman ophiolite) underwent a large tectonic rotation of ~120° after it formed. Serpentinization of the mantle peridotites of this ophiolite could potentially have happened during any or all of the following stages in its evolution: (i) via deep fluid circulation during Late Cretaceous seafloor spreading; (ii) during tectonic rotation after cessation of seafloor spreading; (iii) during Late Cretaceous emplacement onto the Arabian continental margin; and (iv) via reactions with modern meteoric water (via alkaline springs that demonstrably relate to ongoing serpentinization). Results demonstrate that magnetization directions within the Troodos serpentinites are highly variable and include: (i) WNW-directed magnetizations that are inferred to have been acquired during early serpentinization on the seafloor during the Late Cretaceous, that QDM and associated rock magnetic analyses definitely show are carried by magnetite distributed along serpentinite veins; (ii) NW-directed magnetizations inferred to have been acquired partway through the rotation during the Maastrichtian-Paleogene; and (iii) N- and S-directed magnetizations inferred to have been acquired post-rotation in different polarity chrons. Results from the Oman serpentinites (accompanied by results from Oman Fizh, Salahi and Haylayn lavas) demonstrate that that magnetization directions are also highly variable and indicate serpentinization either: (i) during the later stages of rotation but before emplacement; (ii) during emplacement of the ophiolite, due to upwards migration of orogenic fluids from the base of the ophiolite at ~ 75Ma (Feinberg et al., 1999); and (iii) due to interactions with meteoric water while exposed at the surface after emplacement until the present day
Reactive power potential: A contribution of hydropower for the Energy Transition
Get PDFThe growing challenges of climate change and the urgent need to reduce carbon emissions make Germany’s Energy Transition a crucial step in addressing these global issues. Climate change, driven largely by rising CO₂ levels, demands a swift shift to renewable energy to minimise its impact on the environment and society. At the same time, the gradual phase-out of conventional power plants presents significant challenges for the electricity grid, especially in terms of expanding the network and ensuring its reliability. This study explores the critical role of hydropower plants in stabilizing the energy system. In addition to generating renewable energy, hydropower plants are highly adaptable and can play a vital role in ensuring system security by providing reactive power. The research identifies a theoretical potential of 409 MVar inductive and 252 MVar capacitive reactive power in Bavaria’s medium-voltage grids. This highlights the importance of hydropower in addressing the increasing demand for grid stability as conventional power plants are retired. To fully utilise this potential, the study emphasises the need for technical upgrades and changes in regulations. It focuses on challenges related to voltage stability and the control of reactive power, where hydropower’s stability and controllability offer clear advantages. As renewable energy sources like solar and wind become more prominent, their intermittent nature makes the need for reliable grid stabilisation even more pressing. The research also examines the economic and operational aspects of integrating hydropower into reactive power management. It calls for policies and incentives to encourage HPP operators to enhance their capabilities. Modernising equipment and upgrading grid infrastructure are identified as essential steps to align hydropower’s potential with the demands of a renewable energy-focused grid. By balancing technical and economic factors, hydropower can become a cornerstone of a sustainable and decentralised energy system. The findings underscore the importance of collaboration among policymakers, grid operators, and energy producers. Creating a supportive environment for hydropower’s expanded role is essential to achieving the goals of the Energy Transition. This study not only addresses the immediate challenges but also offers solutions that can be adapted to other regions facing similar energy transformation needs. In conclusion, integrating hydropower into reactive power management is a transformative opportunity to enhance the resilience and efficiency of Germany’s electricity grid. The research highlights the importance of aligning technical, regulatory, and economic strategies to fully realize hydropower’s potential. This alignment is key to ensuring the success of the Energy Transition, maintaining grid stability, and reinforcing Germany’s leadership in renewable energy development
CCP-WSI Blind Test Series 5: Numerical Investigation of Isothermal Sloshing in a Circular Tank Using OpenFOAM
Get PDFSloshing dynamics in partially filled tanks is a critical concern across various engineering disciplines, including maritime, aerospace, automotive, and industrial applications. This work concerns a series of sloshing test cases using computational fluid dynamics and represents an individual contribution to the CCP-WSI Blind Test Series 5, in which the submitted results are compared against both physical and alternative numerical solutions. Free surface and centre of gravity measurements are presented and the sensitivity to crucial numerical techniques such as turbulence modelling are assessed. Results suggest that capturing the onset of excitation is particularly sensitive to the choice of turbulence model and in some cases the mesh resolution.In offshore shipping, the storage and transport of liquid gas rely on type ‘C’ tanks, which are engineered to withstand extreme cryogenic conditions and high pressures. These specialised tanks play a crucial role in safely handling liquid gas, ensuring its viability as a large-scale energy carrier. Drawing from this expertise, the aviation industry is exploring alternative fuels to mitigate carbon emissions, with liquid hydrogen (LH2) emerging as a promising candidate, which does not emit carbon dioxide under combustion. Additionally, LH2 exhibits a high specific energy density, nearly three times that of conventional aviation fuel, offering an advantage of reduced fuel mass for the same energy content. However, the cryogenic nature of LH2, necessitating storage at temperatures as low as -253°C, presents challenges. One problem is liquid sloshing, which induces complex fluid motions within partially filled fuel tanks, this can lead to significant pressure variations in a cryogenic fuel tank. Understanding and mitigating pressure variations is critical for ensuring stable fuel delivery to aircraft propulsion systems. Sloshing refers to the free-surface motion of a liquid in a container subjected to external excitation (Ibrahim, 2005).This phenomenon is particularly problematic in cryogenic fuel tanks due to thermal and fluid dynamic interactions. As demonstrated in previous experimental studies (Moran et al., 1994; Arndt et al., 2008; Das amp; Hopfinger, (2009), Ludwig et al., 2013), sloshing can disrupt the thermal stratification between liquid and gaseous phases within the ullage space, leading to thermal destratification. This phenomenon is driven by heat and mass transfer between the phases, leading to condensation and subsequently rapid pressure drops. Such pressure drops can induce structural instability and fuel delivery issues, posing risks to aircraft certification and the overall operational efficiency of LH2-fueled aircraft
Mesoscale Modelling for Investigating Effective Properties and Collective Performance of Geopolymer Concrete
Get PDFConcrete is a versatile construction material which, depending on architectural design and structural analysis, can be shaped into various forms so that requirements for beauty and functions of designed facilities can be met while structural strength of the facilities is sufficient to sustain both gravity and external loadings. It is so favoured by engineers that its consumption is just after water. However, Portland cement – a main ingredient for use in the manufacture of traditional concrete – is quite a “dirty” material which releases a large amount of carbon dioxide in the process of its production. Carbon dioxide is one of the greenhouse gases causing global warming which may be a main factor behind extreme heatwaves seen in the UK and around the world in recent years. To reduce the impact of construction on environment, scientists and engineers are trying their best to propose and investigate novel sustainable materials for the production of concrete.Geopolymer is an inorganic aluminosilicate material which has been conclusively proven in numerous studies to be a greener and more sustainable binder as compared to Portland cement. This elevates attention from many researchers on using it to partially or completely replace Portland cement in the manufacture of concrete products. In order to accelerate applications of geopolymer and widen the industrial utilisation of geopolymer concrete, more research is in dire need of understanding properties and behaviour of geopolymer concrete. Aim of this research is to propose a cost-effective mesoscale modelling technique to predict effective thermal and mechanical properties of geopolymer concrete, and to investigate the collective performance of geopolymer concrete subjected to both thermal and mechanical loadings. With this aim in mind, work of this research is divided into the following six research objectives. (1) To propose a generic mathematical algorithm and develop the MATLAB codes for building up the mesoscale geometric models of geopolymer concrete with realistic and theoretical shapes of aggregate; (2) To predict the effective mechanical properties of geopolymer concrete at ambient temperature using the technique of the proposed mesoscale modelling and then to investigate the damage behaviour of geopolymer concrete subjected to uniaxial compression; (3) To investigate possible factors that may affect the collective performance of geopolymer concrete by means of carrying out parametric analysis on the mesoscale models. (4) To predict the effective thermal conductivity, a property for evaluating the heat transfer capacity of geopolymer concrete, by means of mesoscale modelling; (5) To apply mesoscale modelling to calculate the effective coefficient of thermal expansion of geopolymer concrete; and finally (6) To investigate the coupled behaviour of geopolymer concrete subjected to both thermal and mechanical loadings from the mesoscopic point of view.Results show that the developed codes are capable of generating different types of mesoscale geometric models of geopolymer concrete and the proposed mesoscale modelling technique can well predict thermal and mechanical properties of geopolymer concrete. It is also revealed that this technique can be well applied to investigate the thermo-mechanical behaviour of geopolymer concrete. Based on the contributions demonstrated in this thesis, further research can be carried out to evoke more understanding of geopolymer concrete and boost our confidence in use of geopolymer concrete in more construction structures
The Power of Us: Reflections on Leadership, Inclusion and Change in Education
Get PDFThis paper, originating from the ‘Power of Us!’ conference held in June 2025, reflects on different sessions exploring Exploring Leadership, Wellbeing, and Inclusion in Education. With a particular focus on the experiences of neurodivergent children and those with special educational needs and disabilities (SEND), the session highlighted the urgent need for systemic change. This paper offers an insight into the session, sharing reflections from the discussions and research findings—including the application of Seligman’s PERMA model of positive psychology and the importance of adult social-emotional learning—and calls for action to create a truly inclusive educational system that values all voices and prioritises the wellbeing of both students and staff
Power of Us: Listening to Families
Get PDFThis article, originating from the ‘Power of Us!’ conference held in June 2025, reflects on the session titled ‘Listening to families’ which offered an experienced parent panel, providing a forum for discussion. The session had a particular focus on the experiences of families and their children with neurodivergent and other individual educational needs and the families’ pursuit of genuine co-production with their children’s school. The article offers an insight into the session, sharing reflections from the discussions, and calls for action aimed at creating a truly inclusive educational system
Factors controlling protein metabolism and growth in the common limpet Patella vulgata
No full textThe intertidal environment is a complex and highly dynamic ecosystem shaped by the interaction of strong abiotic and biotic factors. Organisms living in this habitat present marked physiological and behavioural adaptations to cope with extreme and fluctuating conditions, which make this ecosystem the perfect natural laboratory to analyse the effects of biological interactions and physical stressors in ectotherm protein metabolism and growth in the field. Patella vulgata’s ability to maintain aerobic metabolism out of the water, its homing behaviour, its high abundance, and wide geographical distribution facilitates the study of ectothermic physiological processes in the field. Despite the importance of protein metabolism and growth in the fitness of an organism, little is known about the factors governing these physiological parameters in intertidal animals. How organisms manage protein metabolism over fluctuating physical conditions is critical for understanding the physiology and ecology of species inhabiting variable environments and for predicting how they will respond to climate change.This PhD thesis analysed the factors affecting growth, protein metabolism, and oxidative stress in the limpet P. vulgata through a series of laboratory and pioneering field experiments. This project successfully validated the use of the flooding dose technique to measure protein synthesis rates in P. vulgata. The results revealed that P. vulgata is highly adaptable, maintaining aerobic metabolism and presumably growing during emersion, thereby demonstrating resilience to temperature extremes. However, body mass growth and protein retention in P. vulgata are compromised under thermal stress in the laboratory. In the field, protein metabolism and in turn growth are regulated by bottom-up factors, such as temperature and food availability, and top-down controls like oxidative stress. Seasonality and shore height both have profound effects on protein metabolism and growth in P. vulgata, with higher protein synthesis and growth rates reported in low shore limpets, increased metabolic activity in spring and higher protein growth rates in summer, coinciding with gametogenesis. The current thesis provides a foundation for future research on the effects of sea surface temperatures on intertidal communities and the understanding of protein metabolism in the main rocky shore grazer in the Northeast Atlantic
Safety and efficacy of single-dose primaquine to interrupt Plasmodium falciparum malaria transmission in children compared with adults: a systematic review and individual patient data meta-analysis
Get PDFBackground: Adding a single dose of primaquine to artemisinin-based combination therapy (ACT) for the treatment of falciparum malaria can reduce the transmission of Plasmodium falciparum and could limit the spread of artemisinin partial resistance, including in Africa, where the disease burden is greatest. We aimed to compare the safety and efficacy of single-dose primaquine plus ACT between young children (aged \u3c5 years) and older children (aged 5 years to \u3c15 years) and adults (aged ≥15 years), and between low and moderate-to-high transmission areas. Methods: For this systematic review and individual patient data meta-analysis, we searched PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, WHO Global Index Medicus, OpenGrey.eu, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform, from database inception to April 3, 2024, with no language restrictions. We included prospective studies on efficacy against falciparum malaria that enrolled at least one child younger than 15 years and involved a study group given a single dose of primaquine (≤0·75 mg/kg) plus ACT. Studies involving mass drug administration, healthy volunteers, or patients with severe malaria or mixed (with non-falciparum) infections were excluded. For inclusion in the efficacy analysis, data on transmission potential (as determined by gametocytaemia, infectivity, or both) at enrolment and follow-up (day 3, day 7, or day 14) were required; the safety analysis required data on haemoglobin concentrations or haematocrit values at enrolment and at one or more follow-up visits by day 7, any data on adverse events, or both. After independent screening of the search results by two reviewers, the investigators of eligible studies were invited to contribute individual patient data. We quantified day 7 gametocyte carriage, probability of infecting a mosquito, decreases (\u3e25%) in haemoglobin concentration associated with anaemia, and adverse events until day 28 using regression analyses, with random study-site intercepts to account for clustered data. These analyses were registered with PROSPERO, CRD42021279363 (safety) and CRD42021279369 (efficacy). Findings: Of 5697 records identified by the search, 30 studies were eligible for analysis. Of these, individual patient data were shared for 23 studies, including 6056 patients from 16 countries: 1171 (19·3%) young children (aged \u3c5 years), 2827 (46·7%) older children (aged 5 years to \u3c15 years), and 2058 (34·0%) adults (aged ≥15 years). Adding a single low dose of primaquine (0·2–0·25 mg/kg) to ACTs reduced day 7 gametocyte positivity (adjusted odds ratio [aOR] 0·34, 95% CI 0·22–0·52; p\u3c0·001) and infectivity to mosquitoes over time (aOR per day 0·02, 0·01–0·07, p\u3c0·001). No difference was found in the effect of single low-dose primaquine both on gametocyte positivity in young children compared with older children (1·08, 0·52–2·23; p=0·84) and adults (0·50, 0·20–1·25; p=0·14) and between low-transmission and moderate-to-high transmission settings (1·07, 0·46–2·52; p=0·86), and on infectivity to mosquitoes in young children compared with older children (1·36, 0·07–27·71; p=0·84) and adults (0·31, 0·01–8·84; p=0·50) and between low-transmission and moderate-to-high transmission settings (0·18, 0·01–2·95; p=0·23). Gametocyte clearance was also similar for different ACTs (dihydroartemisinin–piperaquine vs artemether–lumefantrine) when combined with a primaquine target dose of 0·25 mg/kg (1·56, 0·65–3·79; p=0·32 at day 7). However, patients given a primaquine dose of less than 0·2 mg/kg with dihydroartemisinin–piperaquine were more likely to have gametocytaemia than those treated with artemether–lumefantrine (5·68, 1·38–23·48; p=0·016 at day 7). There was no increase in anaemia-associated declines in haemoglobin concentration (\u3e25%) at a primaquine dose of 0·25 mg/kg, regardless of age group, transmission setting, and glucose-6-phosphate dehydrogenase status. The risks of adverse events of grade 2 or higher and of serious adverse events were similar between primaquine and no-primaquine groups, including in young children. Interpretation: Regardless of malaria transmission intensity and age group, a single dose of 0·25 mg/kg primaquine is safe and efficacious for reducing P falciparum transmission. These findings underscore the need for primaquine formulations suitable for young children, and also provide supportive evidence to expand the use of single low-dose primaquine in regions with a moderate-to-high transmission rate that are threatened by artemisinin partial resistance. Funding: The EU and the Bill & Melinda Gates Foundation
Languaging the infrathin of the everyday un/clear
No full textThis chapter plays within the moments felt as subject(ivity) formed within actual events, moments Whitehead describes as actual occasions. Moments pulled away from creative becoming, the Deleuze/Guattari conceptualisation of affect, their immanently relational nonbeing, to attune, or retune, into conformations acceptable to what Moten and Harney speak into as logistical capitalism and its assemblage of the proper way to do things.It is thinking within the comprehensibility of logistical capitalism, conversing with Manning’s concept of the clear where we find ourselves languaging: expressing a collective enunciation moving out of the clear bypassing language, a means of “forced improvement in production,” to communicate the unclear, the in-betweenness, the Duchamp/Manning fleeting and pre-articulate moments of the infrathin frictioning in-between the logistical capitalist subject(ivity) attempting to pull us into actual occasions of conforming to its ideology and the irreducibility of experience. To grasp at the uneasy (in)visible borders frictioning the everyday, shaping the ways we exist
Hadronic vacuum polarization for the muon g-2 from lattice QCD: Complete short and intermediate windows
Get PDFWe present complete results for the hadronic vacuum polarization (HVP) contribution to the muon anomalous magnetic moment aμ in the short- and intermediate-distance window regions, which account for roughly 10% and 35% of the total HVP contribution to aμ, respectively. In particular, we perform lattice-QCD calculations for the isospin-symmetric connected and disconnected contributions, as well as corrections due to strong-isospin breaking. For the short-distance window observables, we investigate the so-called log-enhancement effects as well as the significant oscillations associated with staggered quarks in this region. For the dominant, isospin-symmetric light-quark-connected contribution, we obtain aμll,SD(conn)=48.139(11)stat(91)syst[92]total×10-10 and aμll,W(conn)=206.90(14)stat(61)syst[63]total×10-10. We use Bayesian model averaging to fully estimate the covariance matrix between the individual contributions. Our determinations of the complete window contributions are aμSD=69.05(1)stat(21)syst[21]total×10-10 and aμW=236.45(17)stat(83)syst[85]total×10-10. This work is part of our ongoing effort to compute all contributions to HVP with an overall uncertainty at the few-permille level