1,400 research outputs found
Obtaining potential energy surfaces of an der waals molecules
Two different methods were used to obtain a potential energy surface for the Arco molecule. One involved choosing a functional form for the repulsion and dispersion energies whose parameters were determined by a fit to experimental data. A physically justified potential that agreed with experiment could not be obtained. The other method was based on calculating ab initio interaction energies at different configurations of the molecule and interpolating between them. The resulting surface was scaled in the energy and the co-ordinates. Improved agreement was achieved for most observed bound states. Errors in the surface may have been due to an inadequate density of ab initio energies. So, how the molecular configurations chosen for interaction energy calculations affected the potential obtained was investigated. Both the co-ordinate system and the interpolation scheme also significantly affected the quality of surface obtained. The best compromise between accuracy and number of configurations, was points distributed on a regular grid in elliptic co-ordinates with Gauss-Legendre quadrature points in the angular co-ordinate. This information was employed to obtain a potential energy surface for the weakly bound HeOCS molecule which was in close agreement with experiment. A co-ordinate and energy scaling, guided by experiment, was applied to the ab initio surface. Only three scaling parameters were required due to the high quality of the initial surface
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Evaluation by simulation of interpolation and acceleration algorithms for Stepper Motors
Stepper motors are used to control CNC machines for many applications. As well as following the required path precisely, it is also important that the motion be smooth and that the surface speed be controllable. Improved interpolation algorithms for individual straight lines and circular arcs have been developed using distance as a parameter [Chow et al, 2002], [Chow, 2003]. The algorithms control the motor by means of pulses and the generation of the pulse timings is based on the geometry of the shape. For high speeds it is necessary to allow smooth acceleration at the beginning and similar smooth deceleration at the end. Thus, appropriate acceleration and deceleration algorithms have been developed for use with the new interpolation algorithms. This paper describes how simulation has been used to evaluate the new algorithms and compare them with previous algorithms. The algorithms are described for the 2D case but the principle can be extended to 3D
Comparative Perspectives on the Role of National Pride, Identity and Belonging in the Curriculum
In this Special Issue, Comparative Perspectives on the Role of National Pride, Identity and Belonging in the Curriculum, Pedagogy and Experience of Higher Education, papers explore how contemporary issues in democratic education play out in higher education curriculum policy, pedagogy, and the student experience within and across different national contexts [...
Higher Education reform in Myanmar: Neoliberalism versus an inclusive developmental agenda
Myanmar has been transitioning to a parliamentary democracy following a long period of authoritarian military rule, with higher education positioned as a catalyst of and for change. This paper explores the policy reform texts through discourse analysis and the process of their enactment by senior university leaders. Two discourses emerge, one of neoliberalism and the role of globalisation, competition and marketisation. Another adopts traditional Myanmar values and argues for an inclusive, developmental agenda based on local needs using culturally sensitive approaches. The article explores the complimentary and contradictory nature of these approaches and the consequences for reform efforts
Caught between COVID-19, Coup and Conflict—What Future for Myanmar Higher Education Reforms?
On 1 February 2021, Myanmar military dictators seized power from the elected government and halted the country’s budding reform process. This article explores how Myanmar’s higher education (HE) sector was affected by the coup and COVID-19 and how this has resulted in societal conflict. The article reviews first the history of military coups, then the education reforms in general and what was done in HE, before discussing the effects of COVID-19 and the coup on the sector. Voices from HE teaching staff show the tension in the role of HE as a vehicle for reform and promulgation of those in power. The article argues that the national vision propagated by Myanmar’s HE sector is juxtaposed to that propagated by the Tatmadaw, both claiming to represent Myanmar’s future. This research highlights the dual forces of the COVID-19 pandemic and military coup at a crucial time for HE reforms in a fragile, conflict-affected state, with the future of the reform goals of equity and equality of the sector at stake
Asymmetric triplex metallohelices with high and selective activity against cancer cells
Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail ‘triplex’ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 p53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli.
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Curriculum change as transformational learning
Through an evaluation of an institution-wide curriculum change process, this paper analyses how strategic policy is variously enacted in departmental communities. Linguistic ethnography of public, institutional and internal policy documents illuminates departments’ engagement with the change process. With curriculum change positioned as a disorienting dilemma, transformational learning theory provides a lens to analyse the departments’ alignment with the intention of the curriculum change policy. The paper explores the extent to which departments transformed from a disciplinary content-based and high-stakes examination approach to the curriculum to incorporating broader institutional aims and active learning theories into disciplinary language, pedagogy and practices. Three stages of engagement are identified through an evaluation rubric, offering a framework to assess curriculum change initiatives. Implications for educational leaders include the need to integrate institutional strategy with disciplinary experts and expertise and the importance of language adoption as a precursor to implementation
Uist Lagoons Survey
Scotland has around a hundred saline lagoons, coastal lochs that are not quite as saline as the sea. A small number of organisms are confined to these lochs, but most of these are very small and belong to groups that are difficult to identify. A consortium of specialists in identification at the National Museum of Scotland and ecologists sampled most of the saline lagoons on designated sites (SSSI and SAC) in the Uists, the area believed to have the best biodiversity of lagoon organisms in Scotland. The study not only confirmed the presence of these specialist species, but also that they were more widely distributed in the Uists than had been believed. Samples of the organisms have been placed in the permanent collections of the National Museum of Scotland and (for plants) in the Royal Botanic Gardens Edinburgh, where they will be available for future study
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