Three pillars of sustainability: in search of conceptual origins

The three-pillar conception of (social, economic and environmental) sustainability, commonly represented by three intersecting circles with overall sustainability at the centre, has become ubiquitous. With a view of identifying the genesis and theoretical foundations of this conception, this paper reviews and discusses relevant historical sustainability literature. From this we find that there is no single point of origin of this three-pillar conception, but rather a gradual emergence from various critiques in the early academic literature of the economic status quo from both social and ecological perspectives on the one hand, and the quest to reconcile economic growth as a solution to social and ecological problems on the part of the United Nations on the other. The popular three circles diagram appears to have been first presented by Barbier (Environ Conserv 14:101, doi: 10.1017/s0376892900011449, 1987), albeit purposed towards developing nations with foci which differ from modern interpretations. The conceptualisation of three pillars seems to predate this, however. Nowhere have we found a theoretically rigorous description of the three pillars. This is thought to be in part due to the nature of the sustainability discourse arising from broadly different schools of thought historically. The absence of such a theoretically solid conception frustrates approaches towards a theoretically rigorous operationalisation of ‘sustainability’

Contested meanings of public engagement: exploring discourse and practice within a British city council

This article explores local government engagement and communication with citizens in one of the UK’s largest cities from the perspective of a range of actors involved in the engagement process. We establish that a variety of interpretations and contested meanings of engagement exist among professionals involved in different spheres of public engagement. These meanings have different outcomes for the potential voice and influence given to citizens in the city’s democratic existence. We explore what the differing motivations behind the council’s communications and engagement strategies mean for the way that the democratic space of the city is constructed and communicated to citizens. We conclude that there is a need for closer integration of engagement and communications strategies. Integral to the success of such strategies is an empirically informed understanding of what public engagement is, and what skills and practices are necessary to engage with citizens successfully, especially in the reconfigured communication ecology to which new media adds a new dimension

Photo-Induced Current Transient Spectroscopy of Semi-insulating Single Crystal Cs2Hg6S7

The ternary compound Cs2Hg6S7 has shown considerable promise as a wide gap semiconductor for hard radiation detection at room temperature. We report on the measurement of defect levels in Cs2Hg6S7 using photo-induced current transient spectroscopy. We observe a series of defect levels with mean activation energies of 0.053, 0.052, 0.34, 0.35, and 0.46 eV. The defects are attributed to Cs vacancies and Cs and Hg antisite defects. Defect capture cross-sections are in the range 10(-20)-10(-15) cm(2).close0