Fully carbon metasurface: Absorbing coating in microwaves

This is the author accepted manuscript. The final version is available from AIP Publishing via the DOI in this record.The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of porous glassy carbon spheres were experimentally and theoretically investigated in the Ka-band (26–37 GHz) frequency range. The electromagnetic response of such a “moth-eye”-like all-carbon metasurface at a normal incidence angle was modelled on the basis of long-wave approximation. Modelling parameters in the Ka-band were used to estimate and predict the absorption properties of monolayers in free space in the range 1–40 GHz. Experimental and theoretical results demonstrate that a metasurface based on porous glassy carbon spheres is an inert, lightweight, compact, and perfectly absorbing material for designing new effective microwave absorbers in various practically used frequency ranges.The work was supported by Projects FP7-610875 (NAMICEMC, 2013-2017), H2020 RISE 734164 Graphene 3D, and FP7 IRSES project CANTOR (Grant No. FP7-612285). Sijin Li thanks the China Scholarship Council for the financial support under Grant No. 201406510029. Cameron Gallagher and Emma Burgess acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom, via the EPSRC Centre for Doctoral Training in Metamaterials (Grant No. EP/L015331/1)

Public sector commissioning and the third sector: Old wine in new bottles?

Public sector commissioning has risen rapidly to prominence as the central mechanism for the ‘purchase’ of services in an increasingly mixed economy of public services in the UK and this has wide-ranging consequences for non-state actors including those in the third sector. Academic consideration of commissioning has been rather fragmented, concerned with particular service fields or sectors. This paper provides an overview, with a focus on the relationship between the state and the third sector. The paper begins by questioning whether commissioning is really ‘new’ or a continuation of exist- ing trends around procurement and contracting and whether it constitutes a genuinely transformative relationship between the state and third sector. It considers some core debates about the likely impact of commissioning on the third sector and its relationship with the state. In doing so, the paper advances two main arguments: that commissioning remains highly fragmented in policy and practice, between different localities and scales of government; and that there is a tension within commissioning policy between the ‘rhetoric’ of the ‘full cycle’ approach based on needs assessment and planning, and what appears to be an emerging reality of resource-constrained, large-scale and Payment by Results-based contracting. These raise real concerns for organizational and service quality outcomes

Fully carbon metasurface: Absorbing coating in microwaves

The microwave-absorbing properties of a heterostructure consisting of an ordered monolayer of porous glassy carbon spheres were experimentally and theoretically investigated in the Ka-band (26–37 GHz) frequency range. The electromagnetic response of such a “moth-eye”-like all-carbon metasurface at a normal incidence angle was modelled on the basis of long-wave approximation. Modelling parameters in the Ka-band were used to estimate and predict the absorption properties of monolayers in free space in the range 1–40 GHz. Experimental and theoretical results demonstrate that a metasurface based on porous glassy carbon spheres is an inert, lightweight, compact, and perfectly absorbing material for designing new effective microwave absorbers in various practically used frequency ranges

Has the Whitehall Model survived?

The expression 'Whitehall Model' has a certain heuristic value for describing four key features of the British civil service, namely political neutrality, generalism, life-long career paths and a strong policy advisory role. This model has been challenged by politicization, changes in career management and recruitment as well as increasing competition from other sources of policy advice. The UK civil service's role in relation to ministers seems to have become increasingly defined in managerial terms and decreasingly as policy advisers, not least because a range of other individuals and bodies (advisers, consultants, think tanks, party research departments) now share this role. While it appears to be enjoying a diminishing policy role, the senior civil service has not, at least so far, managed to occupy the high ground in its managerial role. The biggest change in the model is a collapse of confidence in the civil service, not only among citizens, but also among politicians and civil servants themselves