Optical binding mechanisms: a conceptual model for Gaussian beam traps

Optical binding interactions between laser-trapped spherical microparticles are familiar in a wide range of trapping configurations. Recently it has been demonstrated that these experiments can be accurately modeled using Mie scattering or coupled dipole models. This can help confirm the physical phenomena underlying the inter-particle interactions, but does not necessarily develop a conceptual understanding of the effects that can lead to future predictions. Here we interpret results from a Mie scattering model to obtain a physical description which predict the behavior and trends for chains of trapped particles in Gaussian beam traps. In particular, it describes the non-uniform particle spacing and how it changes with the number of particles. We go further than simply \emph{demonstrating} agreement, by showing that the mechanisms ``hidden'' within a mathematically and computationally demanding Mie scattering description can be explained in easily-understood terms.Comment: Preprint of manuscript submitted to Optics Expres

Starsat: A space astronomy facility

Preliminary design and analyses of a versatile telescope for Spacelab missions are presented. The system is an all-reflective Korsch three-mirror telescope with excellent performance characteristics over a wide field and a broad spectral range, making it particularly suited for ultraviolet observations. The system concept is evolved around the utilization of existing hardware and designs which were developed for other astronomy space projects

CAMAU Project: Progression Frameworks and Progression Steps

This paper contains information which provides a context for the work of the CAMAU research team based in the Universities of Glasgow and of Wales Trinity Saint David. This information includes an outline of the context of curriculum and assessment arrangements within which the research is situated and provides information on the processes of working with the Pioneer Schools network, a key aspect of the Welsh Government’s commitment to subsidiarity in educational decision making. This paper also includes key findings from the project’s Interim Report (October 2017) ‘Learning about Progression’

Fluctuating Elastic Rings: Statics and Dynamics

We study the effects of thermal fluctuations on elastic rings. Analytical expressions are derived for correlation functions of Euler angles, mean square distance between points on the ring contour, radius of gyration, and probability distribution of writhe fluctuations. Since fluctuation amplitudes diverge in the limit of vanishing twist rigidity, twist elasticity is essential for the description of fluctuating rings. We find a crossover from a small scale regime in which the filament behaves as a straight rod, to a large scale regime in which spontaneous curvature is important and twist rigidity affects the spatial configurations of the ring. The fluctuation-dissipation relation between correlation functions of Euler angles and response functions, is used to study the deformation of the ring by external forces. The effects of inertia and dissipation on the relaxation of temporal correlations of writhe fluctuations, are analyzed using Langevin dynamics.Comment: 43 pages, 9 Figure

Curricular Progression and Pupil Learning: Towards a Method for Understanding how Pupils Progress in Learning Over Time

Over recent years, several countries in Europe and elsewhere have seen a resurgent interest in the concept of learning progression and what it means to progress in learning. Learning progressions, or ‘progression frameworks’, are typically thought about as optimised pathways along which pupils might be expected to progress towards greater sophistication in knowledge and skills. They can be informed by or be the product of research and classroom evidence, and can be used to support effective teaching, learning and formative assessment. They have also been critiqued for imposing a sense of linearity and predictability in learning as well as artificial ceilings that can be narrowing and reductive. While many studies of learning progression are concerned with single concepts or ideas (e.g., progression in understanding the concept of matter), the notion that learning becomes more sophisticated is variously reflected in different country’s curricula. Here, we present a study funded by the Carnegie Trust for the Universities of Scotland (RIG009335) that was undertaken to design a methodological approach for developing a rich understanding pupils’ progression in learning. It is set within the context of Welsh Educational reform and is designed to form part of a future and larger-scale longitudinal study that will follow individual pupils through several years and stages of a national education system in which learning progression is foregrounded. We positioned this study by first exploring, challenging and making explicit our own understandings and assumptions about the nature of learning, its acquisitional and participatory natures and the socio-cultural context of classrooms. Making progress in learning was seen as different to making progress in performance and we distinguish between ‘learning progressions’ as symbolic representations of possible ways learning might evolve, and the substantive learning of pupils which may or may not reflect these

Steps to the Future for 'Curriculum for Wales': Developing Coherence, Co-construction, and Praxis

Wales is in the process of major educational reform. The new curriculum (Curriculum for Wales, CfW) commenced in schools in September 2022. CfW differs from the previous curriculum through its focus on four purposes representing a “shared vision and aspiration” for every learner and by articulating learners' progression through six areas of learning and experience. In contrast to the previous performative culture in Wales (Evans, 2022), CfW suggests a more developmental view of learning. Also central to CfW is the principle of subsidiarity. Similar to ‘new curriculum’ in Finland, Scotland, and the Netherlands, CfW shifts away from top-down policy and gives schools and teachers greater autonomy (Sinnema et al., 2020). Professional understandings of progression in learning, and a recognition that learners start at different points and progress in different ways, are meant to form the basis for schools’ curriculum, assessment, and pedagogy arrangements (Welsh Government, 2021). We engaged in conversations with professionals from across the system to address the following research questions: 1. What influences are there on current and future curriculum realisation? 2. How are educational partners moving their identified priorities forward for curriculum realisation? 3. How can new knowledge from co-construction activity be fed back into the system in ways that are meaningful? In this presentation, we share findings to the research questions and discuss how these inform phase two of our project. Wales has adopted a number of the OECD’s (2018) principles for the future of education systems, and thus insights gained through this research will be of interest to other countries taking similar approaches

CAMAU Project: Progression Frameworks and Progression Steps

This paper contains information which provides a context for the work of the CAMAU research team based in the Universities of Glasgow and of Wales Trinity Saint David. This information includes an outline of the context of curriculum and assessment arrangements within which the research is situated and provides information on the processes of working with the Pioneer Schools network, a key aspect of the Welsh Government’s commitment to subsidiarity in educational decision making. This paper also includes key findings from the project’s Interim Report (October 2017) ‘Learning about Progression’