1,124 research outputs found
Formation of Compressed Flat Electron Beams with High Transverse-Emittance Ratios
Flat beams -- beams with asymmetric transverse emittances -- have important
applications in novel light-source concepts, advanced-acceleration schemes and
could possibly alleviate the need for damping rings in lepton colliders. Over
the last decade, a flat-beam-generation technique based on the conversion of an
angular-momentum-dominated beam was proposed and experimentally tested. In this
paper we explore the production of compressed flat beams. We especially
investigate and optimize the flat-beam transformation for beams with
substantial fractional energy spread. We use as a simulation example the
photoinjector of the Fermilab's Advanced Superconducting Test Accelerator
(ASTA). The optimizations of the flat beam generation and compression at ASTA
were done via start-to-end numerical simulations for bunch charges of 3.2 nC,
1.0 nC and 20 pC at ~37 MeV. The optimized emittances of flat beams with
different bunch charges were found to be 0.25 {\mu}m (emittance ratio is ~400),
0.13 {\mu}m, 15 nm before compression, and 0.41 {\mu}m, 0.20 {\mu}m, 16 nm
after full compression, respectively with peak currents as high as 5.5 kA for a
3.2-nC flat beam. These parameters are consistent with requirements needed to
excite wakefields in asymmetric dielectric-lined waveguides or produce
significant photon flux using small-gap micro-undulators.Comment: 17
Smell you later - the repelling effect of secondary plant compounds against water voles and common voles
Fischer, D., Prokop, A., Wink, M., Mattes, H., Jacob, J
UK Competitiveness Index 2019
First introduced and published in 2000, this UK Competitiveness Index (UKCI) represents the 2019 edition of the report. The UKCI provides a benchmarking of the competitiveness of the UK’s localities2 , and it has been designed to be an integrated measure of competitiveness focusing on both the development and sustainability of businesses and the economic welfare of individuals. In this respect, competitiveness is considered to consist of the capability of an economy to attract and maintain firms with stable or rising market shares in an activity, while maintaining stable or increasing standards of living for those who participate in it.
The above definition makes clear that competitiveness is not a zero-sum game, and does not rely on the shifting of a finite amount of resources from one place to another. Competitiveness involves the upgrading and economic development of all places together, rather than the improvement of one place at the expense of another. However, competitiveness does involve balancing the different types of advantages that one place may hold over another, i.e. the range of differing strengths that the socio-economic environment affords to a particular place compared to elsewhere.
This report publishes competitiveness indices that incorporate the most up-to-date data available in 2019, as well as an updated version of the indices presented in the 2016 report, which provides a means of comparison and an examination of the UK’s changing competitiveness landscape. In light of Brexit, published before the UK’s departure from the EU, it will also act as a future benchmark for the performance of UK localities.
The key findings of the 2019 UKCI are analysed and outlined in the following sections. For those readers interested in the score and rank of a particular locality or localities they may wish to refer directly to Appendix 2, which provides a ranked order list of all localities, and/or Appendix 3, which ranks localities within their relevant regional grouping
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UK Competitiveness Index 2023
The report covers UK Competitiveness Index for 2023. This is a benchmarking study covering the competitiveness of localities (local authority districts) in Great Britain. Measures are also included for Local Enterprise Partnerships (LEPs) and City Regions
Universities and open innovation: the determinants of network centrality
This paper addresses the ‘network’ and ‘open innovation’ paradigms by seeking to examine the factors associated with structural positioning within university–industry networks. Drawing upon a network analysis of knowledge-based ties held by universities across the regions of the UK, it is found that those universities with the most central positions (network centrality) within university–industry network structures also have high rates of relational involvement in activities such as spin-off generation and engagement in externally funded research projects. Some forms of activity, in particular intellectual property protection through patenting, are found to be negatively associated with centrality. Spatial location is largely found to be unrelated to the network centrality of universities. By utilising network centrality as one measure of the open innovation capability of universities, the paper indicates that a range of institutional characteristics and factors tend to either promote or limit the engagement of universities in open innovation practices
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UK Competitiveness Index 2021
First introduced and published in 2000, this UK Competitiveness Index (UKCI) report represents the 2021 edition of the report. The UKCI provides a benchmarking of the competitiveness of the UK’s localities, and it has been designed to be an integrated measure of competitiveness focusing on both the development and sustainability of businesses and the economic welfare of individuals. This report publishes competitiveness indices that incorporate the most up-to-date data available in 2021. These data will largely relate to the period since the UK’s departure from the European Union (EU) and the beginning of the Covid-19 Pandemic and associated economic downturn in 2020. As a comparator prior to these major unforeseen (Covid-19 Pandemic) and foreseen (UK’s departure from EU) economic events, an updated UKCI is also generated for 2018. This UKCI will provide a measure of competitiveness prior to these shocks and before the period of greatest uncertainty associated with the UK’s departure from the EU. This provides a means of comparison and an examination of the UK’s changing competitiveness landscape
Study of the island morphology at the early stages of Fe/Mo(110) MBE growth
We present theoretical study of morphology of Fe islands grown at Mo(110)
surface in sub-monolayer MBE mode. We utilize atomistic SOS model with bond
counting, and interactions of Fe adatom up to third nearest neighbors. We
performed KMC simulations for different values of adatom interactions and
varying temperatures. We have found that, while for the low temperature islands
are fat fractals, for the temperature 500K islands have faceted rhombic-like
shape. For the higher temperature, islands acquire a rounded shape. In order to
evaluated qualitatively morphological changes, we measured averaged aspect
ration of islands. We calculated dependence of the average aspect ratio on the
temperature, and on the strength of interactions of an adatom with neighbors.Comment: 6 pages, 6 figures. Proceedings of 11-th Symposium on Surface
Physics, Prague 200
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