Quality factor assessment of subwavelength resonant cavities at FIR frequencies

Subwavelength resonators at FIR are presented and studied. The structures consist of 1D cavities formed between a metallized (silver) surface and a metamaterial surface comprising a periodic array of silver patches on a silver-backed silicon substrate. The concept derives from recent discoveries of artificial magnetic conductors (AMC). By studying the currents excited on the metamaterial surface by a normally incident plane wave, the nature of the emerging resonant phenomena and the physical mechanism underlying the AMC operation are investigated. Full wave simulations, based on finite element method and time-domain transmission line modelling technique, have been carried out to demonstrate the effective AMC boundary condition and prove the possibilities for subwavelength cavities. The quality factor of the resonant cavities is assessed as a function of the cavity profile. It is demonstrated that the quality factor drops to about 1/8 of the half-wavelength value for lambda/8 resonant cavity.

Water Treatment Goes Underground

This is an invited paper to 'The Chemical Engineer' published by IChemE (UK). The paper summarises the technology on arsenic removal from groundwater, which has been recognised by prestigious Ambani Prize of IChemE (UK).

Compost city: underground music, collapsoscapes and urban regeneration

This paper looks at the recent history of Hulme, Manchester, which during the 1980s was home to many of the most successful bands of the post-punk era. This flourishing of underground music was not planned, however. It emerged, through a complex network of urban forces, some physical, some social. The paper develops the concept of the ‘compost city’ a laissez-faire approach to the management of urban culture, which is oppositional to the current vogue for more hands-on cultural industries management.

Dynamical scattering models in optomechanics: Going beyond the 'coupled cavities' model

Recently [A. Xuereb, et al., Phys. Rev. Lett. 105, 013602 (2010)], we calculated the radiation field and the optical forces acting on a moving object inside a general one-dimensional configuration of immobile optical elements. In this article we analyse the forces acting on a semi-transparent mirror in the 'membrane-in-the-middle' configuration and compare the results obtained from solving scattering model to those from the coupled cavities model that is often used in cavity optomechanical system. We highlight the departure of this model from the more exact scattering theory when the reflectivity of the moving element drops below about 50%.

Review of: Whitehouse, R. 1993 Underground Religion: cult and culture in prehistoric Italy. Accordia Specialist Studies on Italy 1. London, University of London.

Malone , C., . Antiquity, 1993. 67(256): p. 686-7.

Environmental Aspects of Underground Construction and Exploration of Underground Structure – State of the Art

An underground work (such as a tunnel or a cavern) has many, well known, environmental qualities such as: no physical barriers crossing the land, less maintenance costs than an analogous surface structure, less expenses for heating and conditioning; a localized emission of noise, gas, dust during operation and, finally, a better protection against seismic actions.
It cannot be forgotten, anyway, that some negative environmental features are present such as, for example, : perturbation, pollution and drainage of the groundwater; settlements; disposal of waste rock.
In the paper the above mentioned concepts are discussed and analysed to give a global overview of all this aspects.

Right-Wing Violence in Germany: Assessing the Objectives, Personalities and Terror Trail of the National Socialist Underground and the State's Response to It

In the last five years the forces of organised right-wing extremism have made electoral advances across many states in contemporary Europe. Germany has not been immune and the extreme right party, the National Democratic Party of Germany won its first seat in the European Parliament since 1989. The recent successes of the extreme right pose issues for European society about tolerance and immigration policy, but this scene has also been associated with an upsurge in racially motivated political violence and acts of right-wing terrorism. Much of this violence is perpetrated by small neo-Nazi styled groups. This paper looks at the most notorious and recent of such groups to emerge in Germany, the National Socialist Underground. The paper explores the origins and personalities behind this terror cell, provides derails of its criminal activities and murder spree, and questions why it took so long for the authorities to identify the NSU.

Magnetic mirror cavities as terahertz radiation sources and a means of quantifying radiation friction

We propose a radiation source based on a magnetic mirror cavity. Relativistic electrons are simulated entering the cavity and their trajectories and resulting emission spectra are calculated. The uniformity of the particle orbits is found to result in a frequency comb in terahertz range, the precise energies of which are tunable by varying the electron's gamma-factor. For very high energy particles, radiation friction causes the spectral harmonics to broaden and we suggest this as a possible way to verify competing classical equations of motion.

Conflict Management in Public-Private Partnerships: The Case of the London Underground

Public–private partnerships (PPPs) have become common inter-organizational arrangements associated with “new public management.” Discussion about their effective operation has often focused on successful management methods, with less discussion about how these arrangements specifically overcome obstacles and problems. In this article, we seek to address this deficiency in the literature by analyzing the conflict management system employed within the London Underground PPP (when it was still in operation). We conclude by identifying several lessons from this case that we believe should inform the design of such systems, one of which is the role of knowledge management.