871 research outputs found
Searching for belonging: learning from studentsâ photographs about their higher education experiences
Searching for belonging is the transformative individual process of developing connections, making homes and hoping in the ecologies of a community. Belongingness influences academic performance, confidence and well-being. Therefore, understanding how students embody and search for belongingness in their higher education experience provides insights into student agency during their learning and development. Through an arts-based method â photography â we facilitated postgraduate studentsâ reflections on their higher education experience at a UK university during the Covid-19 pandemic. This method decentres the dominant role of (usually English) language in producing knowledge about student experience. Our findings suggest that belonging is constructed through a liminal space of making embodied, material, affective, aesthetic and mental connections to a new environment and is grounded in the humanistic endeavour of being a connected person at a place. The studentsâ photographic insights about belonging are not confined by essentialist boundaries of their nationalities or student status, which might be foregrounded in the existing narratives about (âinternationalâ) students and their experience in UK higher education. Instead, they reflect a humanistic, holistic sense making of studentsâ experience, in which the students are evident as agentive, confident, and capable of home-making and searching for belonging
Clusters, phason elasticity, and entropic stabilisation: a theory perspective
Personal comments are made about the title subjects, including: the relation
of Friedel oscillations to Hume-Rothery stabilisation; how calculations may
resolve the random-tiling versus ideal pictures of quasicrystals; and the role
of entropies apart from tile-configurational.Comment: IOP macros; 8pp, 1 figure. In press, Phil. Mag. A (Proc. Intl. Conf.
on Quasicrystals 9, Ames Iowa, May 2005
The Domination Number of Grids
In this paper, we conclude the calculation of the domination number of all
grid graphs. Indeed, we prove Chang's conjecture saying that for
every , .Comment: 12 pages, 4 figure
Diffraction behaviour of three-component fibonacci Ta/Al multilayer films
A class of quasiperiodic structure three-component Fibonacci (3CF) Ta/Al multilayer films is fabricated by dual-target magnetron sputtering. The microstructure of this film is investigated by transmission electron microscopy and electron and X-ray diffraction. Cross-section transmission electron microscopy demonstrates a well formed layer structure of 3CF Ta/Al superlattices. The electron-diffraction satellite spots, which can be indexed by three integers, correspond to the X-ray diffraction peaks in both position and intensity. The scattering vectors observed in electron and X-ray diffraction are in good agreement with the analytical treatment from the projection method
Transmission-electron microscopy study of the shape of buried InxGa1-xAs/GaAs quantum dots
High-resolution electron microscopy, on-zone bright-field imaging, and image simulation were used to investigate the shape of capped In0.06Ga0.4As/GaAs semiconductor quantum dots. Cross-section [110] high-resolution images suggest that the quantum dots are lens shaped, while the [001] on-zone bright-field images show a contrast that suggests a quantum dot morphology with four edges parallel to [100]. The image simulation, however, suggests that a spherical quantum dot can produce a square-shaped image. These observations lead to the conclusion that the quantum dots in buried In0.6Ga0.4As/GaAs semiconductor heterostructures are lens shaped
2D honeycomb transformation into dodecagonal quasicrystals driven by electrostatic forces
Dodecagonal oxide quasicrystals are well established as examples of long-range aperiodic order in two dimensions. However, despite investigations by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), low-energy electron microscopy (LEEM), photoemission spectroscopy as well as density functional theory (DFT), their structure is still controversial. Furthermore, the principles that guide the formation of quasicrystals (QCs) in oxides are elusive since the principles that are known to drive metallic QCs are expected to fail for oxides. Here we demonstrate the solution of the oxide QC structure by synchrotron-radiation based surface x-ray diffraction (SXRD) refinement of its largest-known approximant. The oxide QC formation is forced by large alkaline earth metal atoms and the reduction of their mutual electrostatic repulsion. It drives the nâ=â6 structure of the 2D Ti2O3 honeycomb arrangement via StoneâWales transformations into an ordered structure with empty nâ=â4, singly occupied nâ=â7 and doubly occupied nâ=â10 rings, as supported by DFT
Oxygen vacancy induced structural variations of exfoliated monolayer MnO2 sheets
We report findings on the structural stability of exfoliated monolayer MnO2 sheets. Our study reveals that monolayer MnO2 sheets display two specific kinds of structural modification under electron irradiation. An atomic reconstruction (2 x 1) and a phase of MnO, induced by ordered oxygen vacancies, were identified by transmission electron microscopy techniques and further characterized by comparison with density-functional theory calculations. These findings are expected to significantly broaden current knowledge of the structural stability of ultrathin layered sheets
Bayesian Probabilistic Numerical Methods in Time-Dependent State Estimation for Industrial Hydrocyclone Equipment
The use of high-power industrial equipment, such as large-scale mixing equipment or a hydrocyclone for separation of particles in liquid suspension, demands careful monitoring to ensure correct operation. The fundamental task of state-estimation for the liquid suspension can be posed as a time-evolving inverse problem and solved with Bayesian statistical methods. In this article, we extend Bayesian methods to incorporate statistical models for the error that is incurred in the numerical solution of the physical governing equations. This enables full uncertainty quantification within a principled computation-precision trade-off, in contrast to the over-confident inferences that are obtained when all sources of numerical error are ignored. The method is cast within a sequential Monte Carlo framework and an optimized implementation is provided in Python
Alloying, elemental enrichment, and interdiffusion during the growth of Ge(Si)/Si(001) quantum dots
Ge(Si)/Si(001) quantum dots produced by gas-source molecular beam epitaxy at 575 degreesC were investigated using energy-filtering transmission electron microscopy and x-ray energy dispersive spectrometry. Results show a nonuniform composition distribution in the quantum dots with the highest Ge content at the dot center. The average Ge content in the quantum dots is much higher than in the wetting layer. The quantum dot/substrate interface has been moved to the substrate side. A growth mechanism of the quantum dots is discussed based on the composition distribution and interfacial structures
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