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Stability of non-premixed turbulent methane flames: Numerical simulations of the critical diameter and flame stability limits
Get PDFA Computational Fluid Dynamics (CFD) model is developed and validated against experimental data to predict the critical diameter and stability limits of non-premixed turbulent methane flames. The critical diameter defines the orifice size beyond which a stable flame persists at all driving pressures and below this pressure stability is pressure-dependent. Flame stability follows a “peninsula” curve of pressure versus release diameter, with sustained flames above the upper and below the lower pressure limits, while the intermediate region represents a blow-out zone where combustion is not sustained. The critical diameter, at the curve's rightmost point, is crucial for predicting sustained flames. Methane releases have been simulated for conditions in the region of the critical diameter, and for diameters and pressures ranging from 15 to 45 mm and 0.01 to 20 MPa, respectively, corresponding to the upper and lower flame stability limits using the realizable k − ε model and EDC combustion model. The simulations accurately captured blow-out and sustained flames, yielding a critical diameter of 42 mm, consistent with experiments. A methane flame at 5.88 MPa gauge through a 50 mm orifice was also simulated, showing flame length and lift-off distance in agreement with experimental observations. These results confirm the model's reliability in predicting methane flame stability, providing valuable insights for safety and combustion applications. This study presents the first CFD-based reproduction of the full methane flame stability curve, validating model reliability across a wide pressure range and providing a predictive tool for future applications, including the assessment of flame stability in methane‑hydrogen mixtures
“Where am I meant to go from here?”: Young people’s experiences of navigating referral processes, waiting lists and access pathways in mental health services
Get PDFBackgroundEarly intervention for mental health problems during youth can contribute to increased quality of life and the reduction in the rates of youth death by suicide. Young people often wait until their distress becomes severe before seeking help and service factors have been identified as impactful in how they access helping interventions.ObjectiveThis aim of this research was to explore young people’s experiences of accessing mental health services and the interventions provided.MethodsConstructivist Grounded Theory methods (Charmaz, 2014) were used to analyse data collected from young people (n = 18) aged 16–25 years and living in the North West of Ireland, exploring their mental health help-seeking experiences to services. Data were collected through a focus group (n = 6) and interviews (n = 14), with two participants taking part in both.FindingsTwo sub-categories were identified, 1. Navigating administration and 2. Accessing helping interventions, and key findings demonstrate that accessing services can be difficult due to convoluted service pathways that can include lengthy referral processes and waiting lists, especially within public healthcare systems. Actual help-seeking pathways were mapped, and analysis revealed the existence of a ‘referral loop’ where young people with severe distress were continuously referred without interim support, which was found to contribute to suicidality and disproportionately affect care-experienced youth. The most common interventions included psychopharmaceuticals and CBT. Participants reported valuing interventions that included collaboration and listening ear support most.ConclusionEnsuring that young people and their families have easier access to developmentally appropriate interventions and timely responses from services is essential in supporting young people with their mental health problems and improving their quality of life, which can reduce negative life outcomes, including death by suicide.<br/
Diet in Pregnancy: A Review of Current Challenges and Recommendations. A British Nutrition Foundation Briefing Paper"
Get PDFPregnancy is a crucial period during which maternal nutrition, weight and lifestyle behaviours have a direct impact on both maternal and fetal health. This briefing paper describes dietary and lifestyle recommendations for women during the preconceptional period and throughout pregnancy, identifying specific factors that can be modified to improve health outcomes for both mother and child. It considers key areas such as nutrient intakes, supplementation, food safety and weight management, and highlights how dietary choices can help reduce the risk of common pregnancy-related conditions. Despite widespread recognition of the importance of a healthy, balanced diet, many women in the UK fall short of recommended intakes for important nutrients, including iron, folate, iodine and vitamin D. These shortfalls are particularly evident among nutritionally vulnerable groups, such as teenagers, women from lower-income households and those experiencing food insecurity; such groups may face barriers to accessing healthy foods and adhering to supplementation guidance. An increasing interest in plant-based diets presents an opportunity to consider a range of dietary patterns that support both maternal health and environmental sustainability. However, such shifts must be carefully managed to ensure adequate intake of nutrients commonly found in animal products, such as vitamin B12, iron, iodine, calcium and long-chain fatty acids. Rates of overweight and obesity among women of childbearing age remain high, reflecting trends in the general population and contributing to growing concern about maternal obesity. Maintaining a healthy weight before and during pregnancy plays a key role in supporting maternal and fetal wellbeing. Both insufficient and excessive weight gain are associated with elevated risks of complications. Excessive weight gain during pregnancy is associated with an increased risk of developing gestational diabetes, hypertensive disorders such as pre-eclampsia, preterm birth and a greater likelihood of long-term obesity in both mother and child. Supporting women to achieve and maintain a healthy weight in the periconceptional period and throughout pregnancy is therefore a public health priority. The antenatal period presents a unique window of opportunity to promote healthier and more sustainable eating patterns, as women are often highly motivated to improve their health and are in more regular contact with healthcare professionals at this time. Yet, research indicates that many women are unaware of dietary recommendations or receive inconsistent advice. To fully harness this opportunity, healthcare providers must be equipped with culturally appropriate, accessible and evidence-based resources to support perinatal conversations around diet, supplementation, physical activity and body weight. Providing appropriate support during the periconceptional and early pregnancy period is essential to addressing health inequalities, improving long-term wellbeing and positively influencing the health of future generations
Using Computer Vision to Apply Activity Recognition Techniques to the Monitoring of Emotional Wellbeing
Get PDFThe World Health Organization predicts that by 2050 those over the age of 60 will account for 22% of the world's population, up from 12% in 2015. Accompanying this change in demographics will be an increase in age-related health conditions, such as frailty, dementia and Parkinson’s disease which require long-term monitoring and treatment. Dementia and Parkinson’s disease are both progressive neurological conditions. Dementia, commonly presents as changes in mood and behaviour and memory problems. The symptoms of Parkinson’s disease include body tremors and slow, impaired movement, as well as depression and anxiety. Being able to monitor the emotions and emotional well-being of those affected by these conditions, on a long-term basis would allow clinicians, carers and family members to observe trends, supporting diagnosis, management, medication and provision of care.A variety of methods are used to recognise emotion, including video analysis to observe visual and audio signals (if present), or wearable devices to observe physiological signals such as ECG, pulse, and temperature. Taking inspiration from a technique that has been used in human activity recognition, our study employs a pose estimation model generated by the open-source tool OpenPose to extract face, body and hand key-points from video and generating features to input into the algorithms that will classify emotion and/or wellbeing state, rather than activity. Our study aims to demonstrate that combining information about facial expression, body posture and hand gestures will improve categorisation of emotion. For this study we use the Multimodal EmotionLines Dataset (MELD), an acted dataset containing 13,848 video clips of utterances from the TV show “Friends”, which have been labelled using 7 emotion categories. This dataset presents challenges similar to those encountered in a real-life dataset, including multiple people in the frame and occlusion.To address the challenge of multiple people in frame, we have incorporated a mechanism, called pyppbox to enable us to track and identify the person whose emotional state we are observing and extract information for just that person in the frame. This is accomplished by training the facial recognition model FaceNet on images of the 6 main Friends characters, before running pyppbox on the dataset. The output generates bounding box coordinates for each person in each frame with an identity label, which we use to isolate the OpenPose key-points for the person of interest. From these key-points we create a set of pose features, including distances and angles as the input into the algorithms that are used to categorize the emotions, starting with LSTM.We present the results of our study, discussing the performance of the combinations of features for categorising emotion, the effectiveness of the tools used for feature extraction and the future development of this approach for long-term observation of emotional wellbeing in age-related health conditions
The effect of different proximities to failure on arterial stiffness following resistance training protocols matched for volume‐load
Get PDFThis study compared acute changes in measures of arterial stiffness (AS) between two resistance training (RT) protocols that were load, volume and rest matched, but differed in intensity of effort. Eleven healthy adults (36.4 ± 6.8 years) performed a RT protocol with high intensity of effort (HE) and a RT protocol with low intensity of effort (LE). The HE protocol consisted of 3 sets of 12 repetitions, while the LE comprised of 6 sets of 6 repetitions. Loading intensity, volume load, and total rest duration were equivalent between the RT sessions. Pulse wave velocity, augmentation index values collected at baseline, immediately post and 15 min post-exercise. HE elicited significantly greater increases in carotid-femoral pulse wave velocity (6.4 ± 0.3 to 7.3 ± 0.5 m/s) when compared to LE (6.6 ± 0.3 to 6.7 ± 0.3 m/s) (p < 0.05). Both HE and LE induced significant increases in augmentation index (13 ± 5.6 to 28.1 ± 9.3%) post exercise (all p < 0.05). These findings demonstrate that RT with a lower intensity of effort attenuate increases in measures of arterial stiffness compared to a RT scheme at higher intensity of effort when volume load and total rest are equalized.</p
AI for NI: A Strategic Overview for the Adoption of Artificial Intelligence in Northern Ireland
Get PDFMedico-Legal Evidence: Survivor Relational Autonomy and Informed Consent in Sexual Assault Examinations
Get PDFSurvivors of sexual violence often consent to forensic medical examinations for medical and legal purposes, including healthcare treatment, trace evidence collection, and documentation of injuries. Internal vaginal examinations, necessary in cases of penetrative vaginal rape, can be invasive and cause trauma. Recent efforts aim to minimise harm through victim- and trauma-centred approaches. Despite this, there are instances where forensic samples lack evidentiary value due to issues like degradation, contamination, tampering, sample backlog, or collection of forensic evidence that is not necessary (for example, in cases of consent and where identification of the perpetrator is not required). However, internal vaginal examinations are still taking place, turning the collection into a potentially harmful, performative process for the survivor. Limited healthcare resources and structural constraints can contribute to these challenges worldwide. This paper examines the British civil law context because of the contemporary global debate around patient autonomy and understanding of informed consent. It considers that much can be learnt from the British approach when ensuring survivors of sexual violence undergoing forensic medical examination are adequately informed
Investigating ICD‐11 adjustment disorder among college students in Taiwan using the Chinese version of the International Adjustment Disorder Questionnaire
Get PDFBackground: The 11th edition of the International Classification of Diseases has redefined adjustment disorder and the International Adjustment Disorder Questionnaire (IADQ) was developed to assess the symptoms and diagnostic criteria. The present study is the first to investigate ICD-11 adjustment disorder using the IADQ in the East Asian context. Methods: We administered standardized self-report measures, including the Chinese version of the IADQ, to a sample of 766 college students in Taiwan, of whom 265 (34.6%) endorsed at least one psychosocial stressor. Results: The two-factor structure of the IADQ reported in previous studies was replicated. The reliability of the two IADQ subscales were high (α =.935 to.948), and they were highly correlated with symptoms of depression, anxiety, and complex PTSD (r s =.69 to.79, p <.001), demonstrating concurrent validity. In this sample, 5.4% of participants met the diagnostic criteria for ICD-11 adjustment disorder. When participants with probable depression (PHQ-9 ≥ 15) were excluded as per the ICD-11 exclusion rules, 15 participants (1.96%) had probable ICD-11 adjustment disorder. Conclusions: The findings suggest that ICD-11 adjustment disorder can be reliably and validly assessed using the IADQ in the Chinese context. Future studies can use the IADQ to further research the disorder in diverse clinical and nonclinical settings.</p
Good workers’ and the moulding of employee voice and silence in Big 4 firms
Get PDFThis article examines voice and silence on workplace problems in Big 4 professional service firms. Based on interviews in Ireland, workers reported problems in relation to workload and hours, underperforming colleagues, mistreatment, pay, leave time, and promotion. Silence was the dominant response reflecting workers' implicit understanding of organisationally desired worker attributes. Where voice occurred, it was individual and informal. Our analysis places voice as a site of antagonistic worker-management relations, and we contribute to the emerging labour process critique of employee resilience as a tool of management control
Surface airflow patterns at a barchan dune field in Hellespontus Montes, Mars
Get PDFMobile barchan dunes are well-developed in a crater in the Hellespontus Montes region on Mars. Previous studies of their temporal evolution show that the barchans maintain their shape and migrate in a uniform pattern. Whereas barchans are typically associated with unidirectional wind regimes, the crater experiences seasonal changes in wind regime, driven by large-scale circulation patterns. Using a multi-scale modelling approach we demonstrate that the effect of upwind mesas are minimal to steering regional wind conditions, beyond the extent of the mesas themselves which limits the effect on the development and maintenance of barchan dunes further downwind. The results of high resolution CFD modelling showed individual barchan dunes had the capability to locally steer oblique wind flows along the orientation of the barchan dunes. We hypothesise that this ability of barchan dunes to ‘steer’ near surface local wind flows, combined with the uni-directional source of sediment at the site allows barchan morphology to persist in Hellespontus Montes, despite being subject to a range of incident wind directions