Platelet Collapse Model of Pulsar Glitches

A platelet collapse model of starquakes is introduced. It displays self-organized criticality with a robust power-law behavior. The simulations indicate a near-constant exponent, whenever scaling is present.Comment: Figures available by sending request to Ivan Schmidt: [email protected]

Electromagnetic Pulse from Final Gravitational Stellar Collapse

We employ an effective gravitational stellar final collapse model which contains the relevant physics involved in this complex phenomena: spherical radical infall in the Schwarzschild metric of the homogeneous core of an advanced star, giant magnetic dipole moment, magnetohydrodynamic material response and realistic equations of state (EOS). The electromagnetic pulse is computed both for medium size cores undergoing hydrodynamic bounce and large size cores undergoing black hole formation. We clearly show that there must exist two classes of neutron stars, separated by maximum allowable masses: those that collapsed as solitary stars (dynamical mass limit) and those that collapsed in binary systems allowing mass accretion (static neutron star mass). Our results show that the electromagnetic pulse spectrum associated with black hole formation is a universal signature, independent of the nuclear EOS. Our results also predict that there must exist black holes whose masses are less than the static neutron star stability limit.Comment: 9 pages, 8 figures, to be published in Astronomy and Astrophysic

Epitaxial strain and the magnetic properties of canted antiferromagnetic perovskite NaNiF3 thin films

The perovskite crystal structure is known to exhibit a multitude of interesting physical phenomena owing to the intricate coupling of the electronic and magnetic properties to the structure. Fluoroperovskites offer an alternative chemistry to the much more widely studied oxide materials, which may prove advantageous for applications. It is demonstrated here for the first time that the antiferromagnetic perovskite fluoride, NaNiF3, can be synthesized in thin film form. The films were grown via molecular beam epitaxy on SrTiO3 (100) substrates to produce high quality epitaxial films in the thickness range of 5-50 nm. The Pnma structure of the films was confirmed by x-ray diffraction. There was a decrease in the out-of-plane lattice spacing from the bulk value corresponding to a maximum strain of 1.7% in the thinnest film. Canted antiferromagnetism was measured in all films using magnetometry and a negative change in the antiferromagnetic ordering temperature of ΔTN = - 9.1 ± 0.7 K was observed with increasing strain

Eigenvalues of the Laplacian of a graph

Let G be a finite undirected graph with no loops or multiple edges. The Laplacian matrix of G, Delta(G), is defined by Delta sub ii = degree of vertex i and Delta sub ij = -1 if there is an edge between vertex i and vertex j. The structure of the graph G is related to the eigenvalues of Delta(G); in particular, it is proved that all the eigenvalues of Delta(G) are nonnegative, less than or equal to the number of vertices, and less than or equal to twice the maximum vertex degree. Precise conditions for equality are given

Global partnerships in nursing - a qualitative study in lessons for success

Global nursing partnerships can develop cultural competence and standardisation across international nurse education programmes. Issues of context, cultural awareness and modes of engagement can influence the success of international collaboration. The ‘Supporting Internationalisation of Traineeships in the Healthcare Sector’ project, funded from 2017, brought together nine international partners from Finland, Poland, Spain and the UK to develop a pan-European quality audit process for clinical learning environments. As part of the evaluation, eight project partners were interviewed about the project and their criteria for a successful global partnership. The interviews allowed insight into previously hidden aspects of implementation. The importance of a scoping period for nursing global partnerships was highlighted that built on cultural diversity to explore common understandings. Attention to the use of prior expertise in internationalisation, or project objectives, could accelerate a global partnership to achieve a greater potential in its outcomes and cultural sensitivity. Framed in a clear structure, it is possible for global partnerships to embed ownership, autonomy and individual voice in partner organisations. The research concludes that only by growing international champions through funded and well constituted projects, that a genuine impact on the global health and educational needs in nursing can be met

The international focus—a neglected curriculum in global undergraduate nursing

International learning in undergraduate global nurse education is recognised for promoting essential cultural competence. This can be addressed both at university; through the increasing use of collaborative technology and in practice, where the impact of international placements has promoted cultural sensitivity and outward student mobility. The authors debate the barriers that impede students’ desire to take up international placements and review initiatives to promote a greater investment in this experience. The complexity and lack of transcultural principles that govern an international placement exchange have been addressed by one initiative to produce a robust pan-European quality audit process for clinical learning environments. In conclusion, the authors call for a greater and evaluated effort to increase global understanding and learning in the context of the COVID-19 response