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Ultrasonic metrics for large-area rapid wrinkle detection and classification in composites
No full textDue to their high strength-to-weight ratio, composite materials are now in use in many high-stress applications, particularly where light weight is also a requirement. In these situations, the detrimental knock-down in mechanical strength due to an out-of-plane wrinkle defect can have serious consequences and is the reason for a requirement to rapidly detect any such wrinkles at manufacture. Unfortunately, current ultrasonic inspection techniques used for quality control at manufacture are not sensitive enough to detect these wrinkles above coherent structural noise variations. This paper exploits the ply resonance that is a characteristic of multi-layer structures to generate two new metrics for both detection and classification of out-of-plane wrinkles, due to their perturbations of the ply spacing. These can be measured at every location on a structure using the instantaneous frequency, which is the rate of change of phase in the pulse-echo ultrasonic response. The proposed two new metrics for detection and classification of wrinkles are mean spacing and spacing difference and they can be applied to each waveform in real time, as it is acquired. Use of an analytical model to predict the ultrasonic response of the structure has allowed an understanding of how these metrics will be affected by various wrinkle types and how they can not only detect wrinkles but also classify the type of wrinkle and provide an approximate indication of severity. Three main types of wrinkle are considered: classic wrinkles near the mid-plane of a structure, back-surface wrinkles formed from a resin bulge near the back of a structure and folded wrinkles where several plies can be folded over completely in the bulk of the structure. Both simulations and experimental results demonstrate the effectiveness of these metrics on various types of structure, including carbon-fibre and hybrid carbon/glass-fibre composites with a range of ply thicknesses and wrinkle types
Sharing stories, food and passports: forced migration, museum and memory activism in contemporary Germany
No full textThis article uses the online exhibition ‘Arriving: Life after Forced Migration’ by the Marienfelde Refugee Center Museum in Berlin as a case study to investigate how museum activism can contribute to creating and disseminating memories about contemporary forced migration. Employing a close visual and textual analysis of the online exhibition combined with insights from recent discourses on museum activism, migration and memory studies, the article explores which forms of memory the exhibition creates, how these memories emerge and to which end they are used. The analysis firstly illustrates how the exhibition creates a space for communicative memory to surface within the portrayed refugee families through the sharing of stories, objects and food from ‘home’. Secondly, it goes on to argue that the exhibition engages in memory activism by humanizing the portrayed individuals, exposing discriminatory state practices and challenging the audience through provocative questions. Thirdly, the article submits that this online exhibition contributes to a growing transnational archive of forced migration memories. Comprised of a multitude of online platforms dedicated to collecting, preserving and sharing forced migration stories, this archive stimulates multidirectional memory making and allows counter narratives to surface within an increasingly divided Europe
A qualitative study exploring barriers and facilitators in deceased organ donation process among transplant coordinators in India
Get PDFAlthough India's organ donation rate is less than 1 per million population, significant disparities exist between the regions and centres within the country, leading to varying consent rates among different organ donation centres. Therefore, this study aimed to understand the experience of transplant coordinators and their barriers and facilitators in the deceased organ donation process across various organ donation centres in India. A phenomenological study using interviews was conducted among fourteen transplant coordinators purposefully recruited from public and private organ donation centres in India, with experience between six years and more than a decade. Audio recordings were transcribed and analysed using framework analysis. Five themes were identified namely: (1) supportive management policies, (2) infrastructure for the deceased organ donation process, (3) delays in the processing time, (4) active involvement in the identification process, and (5) explaining the concept of brain death. The study identifies that implementation priorities include strengthening teamwork, streamlining processes, optimising infrastructure for sensitive discussions, efficient donor identification, and empathetic handling of donor families' grief stages. Collaborating with law enforcement, applying successful medico-legal strategies, improving family communication, and clarifying brain death concepts ethically and legally can boost consent rates, fostering informed decisions and possibly achieving self-sufficiency in deceased organ donation
Attachment insecurity, bullying victimisation in the workplace, and the experience of burnout
Get PDFIntroduction Although burnout is perhaps the most frequently reported work-related correlate of attachment insecurity, the role of mitigating variables in that link is less well researched. Objective The paper investigates the mediational role of workplace bullying and perceived social support in the link between attachment insecurity and burnout. It was hypothesised that insecurely attached employees would develop burnout via three pathways: (a) by becoming the victims of workplace bullying, (b) by perceiving relatively low support from managers and colleagues due to their attachment insecurity, and (c) by perceiving lower support from managers and colleagues due to them having been bullied. Method Two hundred and twenty-two employees from various completed the following questionnaires: Experiences in Close Relationships Questionnaire – Revised, Revised Negative Acts Questionnaire, Social Support Scale, Maslach Burnout Inventory – General Survey. Results SEM analysis suggested that the two models tested had a good fit, indicating different pathways from bullying to burnout depending on type of attachment insecurity. Conclusion Findings could inform interventions empowering victims of bullying and help organisations deal with this serious problem
An accidental sociologist: a reflection on working-class education and becoming an adult learner
No full textHigher education should be a social good for everyone and, despite the intentions of university policy on inclusion and diversity with schemes on widening participation, the truth is that for working-class students, university is still a place where they encounter prejudices and feelings of exclusion. This article uses the method of autoethnography and personal experience to show and to argue that class inequality and the education system are still connected. It argues that policies relating to inclusion or exclusion are not adequate and instead the working-class lens, the experiences of working-class learners and teachers should be valued pedagogy rather than devalued ‘baggage’ that should be left behind
Over the kitchen table: British storytelling as working-class art, belonging and resistance
No full textThis article introduces a contemporary art and storytelling project that took place in January 2024 in Bestwood Village, an ex-coal community, showing a televised play filmed in the village (1963) written by Dennis Potter, Stand Up, Nigel Barton, about the son of a coal miner gaining a place at Oxford University during this period of social change. The project and the article show that the art of working-class storytelling is both political and personal, and despite the lack of working-class voices in the arts, in the culture industries and in academia, small storytelling events such as this one play an important part in strengthening working-class communities
Half of Atlantic reef-building corals at elevated risk of extinction due to climate change and other threats
Get PDFAtlantic reef-building corals and coral reefs continue to experience extensive decline due to increased stressors related to climate change, disease, pollution, and numerous anthropogenic threats. To understand the impact of ocean warming and reef loss on the estimated extinction risk of shallow water Atlantic reef-building scleractinians and milleporids, all 85 valid species were reassessed under the IUCN Red List Categories and Criteria, updating the previous Red List assessment of Atlantic corals published in 2008. For the present assessment, individual species declines were estimated based on the modeled coral cover loss (1989–2019) and projected onset of annual severe bleaching events (2020–2050) across the Atlantic. Species traits were used to scale species’ relative vulnerability to the modeled cover declines and forecasted bleaching events. The updated assessments place 45.88%–54.12% of Atlantic shallow water corals at an elevated extinction risk compared to the previous assessments conducted in 2008 (15.19%–40.51%). However, coral cover loss estimates indicate an improvement in reef coverage compared to the historic time-series used for the 2008 assessments. Based on this, we infer that, although remaining dangerously high, the rate of Atlantic reef coral cover decline has surprisingly slowed in recent decades. However, based on modeled projections of sea-surface temperature that predict the onset of annual severe bleaching events within the next 30 years, we listed 26 (out of 85) species as Critically Endangered in the IUCN Red List. Each of these species had previously been listed under a lower threatened category and this result alone highlights the severe threat future bleaching events pose to coral survival and the reef ecosystems they support
Integrating metadiscourse analysis with transformer-based models for enhancing construct representation and discourse competence assessment in L2 writing: a systemic multidisciplinary approach
No full textIn recent years, large-scale language test providers have developed or adapted automated essay scoring systems (AESS) to score L2 writing essays. While the benefits of using AESS are clear, they are not without limitations, such as over-reliance on frequency counts of vocabulary and grammar variables. Discourse competence is one important aspect of L2 writing yet to be fully explored in AEE application. Evidence of discourse competence can be seen in the use of Metadiscourse Markers (MDM) to produce reader-friendly texts. The article presents a multidisciplinary study to explore the feasibility of expanding the construct representation of automated scoring models to assess discourse competence in L2 writing. Combining machine learning, automated textual analysis and corpus-linguistic methods to examine 2000 scripts across two tasks and five proficiency levels, the study investigates (1) in addition to frequency and range, whether accuracy of MDM is worth pursuing as a predictive feature in L2 writing, and (2) how identification and classification of MDM use might be fed into developing an automated scoring model using machine learning techniques. The contributions of this study are three-fold. Firstly, it offers valuable insights within the context of Explainable AI. By integrating MDM usage and accuracy into the scoring framework, this research moves beyond frequency-based evaluation. This study also makes significant contributions to the current understanding of L2 writing development that even lower-proficiency learners exhibit evidence of discourse competence through their accurate use of MDMs as well as their choice of MDMs in response to genre. From the perspective of expanding the construct representation in automated scoring systems, this study provides a critical examination of the limitations of many AEE models, which have heavily relied on vocabulary and grammar features. By exploring the feasibility of incorporating MDMs as predictive features, this research demonstrates the potential for construct expansion of L2 AEE. The results would support test providers in developing competence tests in various contexts and domains including manufacturing, medicine and so on
Social worker decision-making: a framework for legally literate accountable practice
No full textSocial workers make decisions every day involving the protection of children and/or adults who are at risk of, or are experiencing, abuse and neglect, exercising power and authority derived from law. Social workers must act within the law: "doing things right." Accountable, legally literate practice additionally includes standards from administrative law when statutory duties are used. However, decision-making frequently also raises ethical dilemmas, including whether, when, and how to intervene in people's lives. Practice must, therefore, be ethically literate: "doing right things." Human rights, equality, and social justice issues will also feature in social work decision-making: "right thinking." This chapter presents a framework for social worker decision-making that is legally and ethically, but also emotionally, relationally, organizationally and knowledge, literate. It proposes that this framework is transferable across the different jurisdictions within which social workers practice, and that it helps social workers to make good as well as lawful decisions
Observation of gallium droplets directly formed on GaAs substrate by in-situ laser irradiation
No full textIn this study, following the deposition of a 500nm GaAs buffer layer, the GaAs substrate was irradiated in MBE with an in situ laser shooting at a very low temperature of around 12°C. We carefully observed the morphology evolution of the irradiated surface with different pulse energy varying from 20mJ to 50mJ. After being pulsed-irradiated with 20mJ, a density of Ga droplets as high as 7.2×1010/cm2 was directly formed on the surface. The droplets have a height range of 1.0nm to 4.1nm (averaging at 2.4nm) and a width range of 15.7nm to 39.2nm (averaging at 28.1nm). With increasing irradiation energy, it is observed the droplet density will gradually decrease from 2.2 × 1010/cm2, 1.2 × 1010/cm2 to 5.2 × 109/cm2 while the size (average width/height) will continue to grow up from 64.1nm/8.2nm, 63.3/9.2nm to 76.1nm/12.2nm, respectively corresponding to exposure energy from 30mJ, 40mJ to 50mJ. The results demonstrate the successful provision of a new technology to generate Ga droplets on the surface of GaAs directly through in-situ pulsed laser irradiation without the need of epitaxial growth. Furthermore, both the resulting density and size can be easily and effectively adjusted by varying the laser energy. Additionally, this technique offers significant advantages such as low cost, free of contamination and defects and high controllability. Therefore, we believe this technology may find great application prospects for nano-fabrication of semiconductor quantum structures and devices
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