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Through-thickness modelling of metal rolling using multiple-scales asymptotics
No full textA new semi-analytic model of the metal rolling process is introduced, which, for the first time, is able to predict the through-thickness stress and strain oscillations present in long thin roll-gaps. The model is based on multiple-scales asymptotics, assuming a long thin roll-gap and a comparably small Coulomb friction coefficient. The leading-order solution varies only on a long lengthscale corresponding to the roll-gap length and matches with slab models. The next-order correction varies on both this long lengthscale and a short lengthscale associated with the workpiece thickness, and reveals rapid stress and strain oscillation both in the rolling direction and through the thickness. For this initial derivation, the model assumes a rigid perfectly-plastic material behaviour. Despite these strong assumptions, this model compares well with finite element simulations that employ more realistic material behaviour (including elasticity and strain hardening). These assumptions facilitate the simplest possible model to provide a foundational understanding of the complex through-thickness behaviour observed in the finite element simulations, while requiring an order of only seconds to compute. This model can form the foundation of further improved models with more complicated mechanics in the future. Matlab code for evaluating the model is provided in the supplementary material.</p
Complement 3 (C3) within the hypothalamic arcuate nucleus is a potential key mediator of the effect of enhanced nutrition on reproductive development in young bull calves
No full textBackground Reproductive development may be advanced in bull calves through enhanced dietary intake during the early life period. This effect between enhanced nutrition with subsequent earlier reproductive development is orchestrated through signalling within the hypothalamic-pituitary-testicular axis. Within the hypothalamus, the arcuate nucleus (ARC) is crucial for the integration of peripheral metabolic status with subsequent gonadotropin releasing hormone (GnRH) signalling; however, the precise molecular control regulating this effect is not fully known. The aim of this study was to evaluate the global transcriptomic and proteomic responses to varied plane of nutrition during early calf-hood in young dairy bull calves. Additionally, we sought to integrate these ‘omics’ datasets to determine key genes and proteins contributing to earlier reproductive development. Between 2–12 weeks of age, 30 Holstein-Friesian bull calves (mean age: 17.5 days; mean bodyweight 48.8 kg), were offered either a high or moderate plane of nutrition with 15 calves in each group. At 12 weeks of age, all calves were euthanised and the ARC tissue isolated from each calf. The ARC tissue was then used for global transcriptomic (miRNAseq and mRNAseq) and proteomic analyses. Results Bioinformatic analyses were undertaken to determine differentially expressed transcripts (FDR 1.5) between the dietary treatment groups, resulting in the identification of 1 differentially expressed miRNA (miR-2419-3p) and 83 differentially expressed mRNA in the ARC region. mRNA target gene prediction identified Complement 3 (C3) as a target of miR-2419-3p, suggesting a relationship between the two transcripts. Furthermore, through a co-regulatory network analysis conducted on the proteomics dataset, C3 was revealed as a hub protein. Additionally, through the proteomic network analysis, C3 was interacting with proteins involved in both insulin and GnRH signalling, highlighting a potential role for C3 in mediated the effect of enhanced nutritional status with earlier reproductive development within the ARC. Conclusion This study highlights an effect of altered plane of nutrition in early life on the molecular control of the hypothalamic ARC. Additionally, results generated suggest a potential role for the C3 gene in mediating the interaction between enhanced metabolic status with reproductive development within the ARC, regulated by miR-2419-3p</p
From Tinkering to Take-off… and the Journey Home
No full textPresentation delivered at The All-Ireland Scratch National Finals 2025.</p
Is the relationship between chronic pain and mortality causal? A propensity score analysis
No full textChronic pain is a serious and prevalent condition that can affect many facets of life. However, uncertainty remains regarding the strength of the association between chronic pain and death and whether the association is causal. We investigate the pain–mortality relationship using data from 19,971 participants aged 511 years in the 1998 wave of the U.S. Health and Retirement Study. Propensity score matching and inverse probability weighting are combined with Cox proportional hazards models to investigate whether exposure to chronic pain (moderate or severe) has a causal effect on mortality over a 20-year follow-up period. Hazard ratios (HRs) with 95% confidence intervals (CIs) are reported. Before adjusting for confounding, we find a strong association between chronic pain and mortality (HR: 1.32, 95% CI: 1.26-1.38). After adjusting for confounding by sociodemographic and health variables using a range of propensity score methods, the estimated increase in mortality hazard caused by pain is more modest (5%-9%) and the results are often also compatible with no causal effect (95% CIs for HRs narrowly contain 1.0). This attenuation highlights the role of confounders of the pain–mortality relationship as potentially modifiable upstream risk factors for mortality. Posing the depressive symptoms variable as a mediator rather than a confounder of the pain–mortality relationship resulted in stronger evidence of a modest causal effect of pain on mortality (eg, HR: 1.08, 95% CI: 1.01-1.15). Future work is required to model exposure–confounder feedback loops and investigate the potentially cumulative causal effect of chronic pain at multiple time points on mortality.</p
Structure-property correlations in CZTSe domains within semiconductor nanocrystals as photovoltaic absorbers
No full textSemiconductor nanocrystals (NCs) are promising materials for various applications. Two of four recently identified CuZn SnSe (CZTSe) domains demonstrate metallic character, while the other two exhibit semiconductor character. The presence of both metallic and semiconductor domains in one NC can hugely benefit future applications. In contrast to traditional band gap studies in the NC community, this study emphasizes that NC domain interfaces also affect the electronic properties. Specifically, the measured band gap of a tetrapod-shaped CZTSe NC is demonstrated to originate from two specific domains (tetragonal I4 and monoclinic ̄ P1c1 Cu2ZnSnSe4). The heterojunction between these two semiconductor domains exhibits a staggered type-II band alignment, facilitating the separation of photogenerated electron-hole pairs. Interestingly, tetrapod NCs have the potential to be efficient absorber materials with higher capacitance in photovoltaic applications due to the presence of both semiconductor/semiconductor interfaces and metal/semiconductor “Schottky”-junctions. For the two photo-absorbing domains, the calculated absorption spectra yield maximum photon-absorption coefficients of about 105 cm−1 in the visible and UV regions and a theoretical solar power conversion efficiency up to 20.8%. These insights into the structure-property relationships in CZTSe NCs will guide the design of more efficient advanced optical CZTSe materials for various applications.</p
Analysing kinematic data from recreational runners using functional data analysis
No full textWe present a multivariate functional mixed effects model for kinematic data from a large number of recreational runners. The runners’ sagittal plane hip and knee angles are modelled jointly as a bivariate function with random effects functions accounting for the dependence among bilateral measurements. The model is fitted by applying multivariate functional principal component analysis (mv-FPCA) and modelling the mv-FPCA scores using scalar linear mixed effects models. Simulation and bootstrap approaches are introduced to construct simultaneous confidence bands for the fixed effects functions, and covariance functions are reconstructed to summarise the variability structure in the data and thoroughly investigate the suit?ability of the proposed model. In our scientific application, we observe a statistically significant effect of running speed on both joints. We observe strong within-subject correlations, reflecting the highly idiosyncratic nature of running technique. Our approach is applicable to modelling multiple streams of smooth biomechanical data collected in complex experimental designs.</p
Boosting the thermochemical energy storage performance of Limestone by adding Mayenite
No full textLong-duration energy storage (LDES) systems play a critical role in the integration of intermittent renewable energy sources into the grid. Thermochemical energy storage (TCES) systems, particularly Limestone ones, offer promising solutions due Limestone’s high energy storage density and cost-effectiveness. However, the cycling performance of Limestone is hindered by sintering phenomena and pore plugging. This paper explores the enhancement of Limestone’s TCES performance by incorporating Mayenite, a mesoporous ternary oxide, as an additive. Mayenite can improve the cycling performance of Limestone by enhancing: (1) the Ca2+ ion migration at high temperatures promoting the carbonation reaction and (2) the CO2 diffusion as shown by the carbonation reaction rate analysis of the mixture samples. In detail, three different Mayenite samples with unique Ca to Al ratios were synthesized and added to Limestone in varying concentrations. The mixture sample containing 5 % Mayenite (with a lower Ca to Al ratio) enhanced 2.5 times Limestone’s energy storage performance after 40 cycles, boosting it from 455 kJ/kg to 1137 kJ/kg. Characterization techniques including X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis provide insights into the structural and kinetic changes induced by Mayenite addition. On the other hand, Density Functional Theory Calculations showed that migration of Ca2+ ions is promoted at high temperatures, improving the carbonation reaction of Limestone. The results demonstrate the potential of Mayenite as an effective additive for improving the performance of Lime stone TCES systems, paving the way for more efficient and reliable long-duration energy storage solutions.</p
Generation apprenticeships – a perspective through the lens of industry learners
No full textApprenticeship pathways are widely recognised as effective for earning while learning and acquiring practical and theoretical skills on the job. The rise of consortia-led apprenticeships reflects growing recognition by educational institutions, government bodies, and industry of the benefits of combining work, learning, and academic awards. However, there is a notable lack of published literature on the unique experiences of apprentices in third-level education, particularly in consortia-led supply chain programmes. This study seeks to fill that gap by offering insights to establish best practices and enhance the success of the supply chain apprenticeship programme. It examines experiences from 67 apprenticeship learners across various industries. Understanding apprentices’ journeys, from their initial awareness of programmes to the support they receive, while identifying the challenges they face is essential. This research offers valuable insights for all stakeholders to positively influence the effectiveness of future consortia-led supply chain apprenticeships.</p
Phosphorus fractionation of dairy processing waste recycled fertilizers reveals inadequacy of the standards, measurement and testing (SMT) protocol
No full textThe Standards, Measurements and Testing (SMT) protocol is widely used to fractionate phosphorus (P); however, it lacks the focus on defining the solubility of P-fractions, which is usually performed independently. In this paper, the addition of a separate pre-wash step with H2O as a first step prior to the SMT protocol was tested to account for the solubility of P. Results were compared to a control unmodified SMT experiment. The differences in P-fractions were analyzed to determine the origin of the readily available P (soluble P). Six different dairy processing waste treatment products were investigated in the form of sludge, hydrochar, and ash. Water-soluble P (WSP) was correlated with weakly bound calcium (Ca), aluminum (Al) and iron (Fe). However, the SMT protocol failed to correctly identify the different pools of P as unexpected correlations were found between P and Ca, Al and Fe. Moreover, large concentrations of organic P were present in ashes (>10 mg P g−1). The organic P fraction included substantial amounts of Fe that correlated highly with P (R2 = 0.84). No association between WSP and any of the pools of P defined by SMT was detected, with the exception of total P and inorganic P. The paper concludes that SMT erroneously classifies P into different discrete fractions across various recycled P-products with fertilizer potential. A critical reevaluation of the SMT protocol is recommended, by abandoning the categorization of P into discrete pools and switching to solvent-based categories referring to the chemicals used in each extraction. Highlights ● SMT fractionation protocol was modified to assess water soluble phosphorus ● The modified SMT protocol was performed on 6 different P-recycled products (fertilizers) ● SMT protocol fails to identify correctly different fractions of phosphorus ● A critical reevaluation of SMT protocol is recommended</p
Developing skill within the context of a Game-Based Approach
No full textLimited research has examined continued skill development in adult high-performance sport. In addition, while game-based approaches emphasise the concurrent development of technical excellence and tactical nous, there is a lack of clarity in relation to how coaches develop skill within a games-based approach. As such, this paper explored coaches’ understanding of skill and their approaches to the development of skill within high-performance cohorts through a game-based approach. Individual, semi-structured interviews were conducted with eight coaches with experience coaching at the highest level of Gaelic football; these coaches self-identified as adhering to a game-based approach, albeit not to a particular framework. Reflexive thematic analysis was applied to the resulting transcripts. The analysis identified two key challenges coaches faced in relation to skill development through a game-based approach: competing priorities for coaches in relation to team preparation within training sessions, compounded by competing priorities for players in terms of athletic development outside of training sessions. Despite these competing priorities, the coaches endorsed skill development as an important function of the high-performance coach and reported a sophisticated definition of skill. The coaches described a variety of activities which were used to support players’ development of skill, consistent with their espoused games-based approach to coaching. However, more sophisticated game design, better integration of unopposed activities and games, developing player self-regulatory skills and enhanced coherence between coaches appear to be ways in which skill development could be enhanced to address the challenges coaches identified and maximise the benefits of employing a game-based approach.</p