Sustainability study of the application of geosynthetic clay liners in hostile and aggressive environments

This paper discusses the sustainable performance of geosynthetic clay liners (GCLs) which are popularly specified as “leachate retaining” or as “water proofing” membranes in the geo-environmental construction industry. Geosynthetic clay liners (GCLs) are composite matting comprising of bentonite clay with two covering geosynthetics. These are innovative labour saving construction material, developed over the last three decades. The paper outlines the variety of Geosynthetic Clay Liners (GCLs) can be classified essentially into two distinctly different forms viz; (a) air dry (< 8% m/c) with granular or powdered bentonite or (b) bentonite cake factory prehydrated to a moisture content (~40% m/c) beyond its shrinkage limit and vacuum extruded as a clay cake to enhance its sustainable performance. The dominant mineral in bentonite clay is the three-layered (2:1) clay mineral montmorillonite. High quality bentonites need to be used in the GCL manufacture. Sodium montmorillonite has the desired characteristic of high swelling capacity, high cation exchange capacity and the consequently very low hydraulic conductivity, providing the basis for the hydraulic sealing medium in GCLs. These encapsulate the active montmorillonite clay minerals which depend on the water and chemical balance between the sealing element and the surrounding geo environment. Quantitative mineralogical analyses and an assessment of the adsorbed cation regime, diffusion coefficients and clay leachate compatibility must necessarily be an integral part of the site appraisal to ensure acceptable long term sustainability and performance. Factors influencing the desired performance of bentonite in the GCLs placed in difficult construction and hostile chemical environments are discussed in this paper. Accordingly, the performance specifications for GCLs are identified and the appropriateness of enhancing the cation exchange capacity with polymer treatment and the need for factory prehydration of the untreated sodium bentonite is emphasised. The advantage of factory prehydrating the polymer treated bentonite to fluid content beyond its shrinkage limit and subsequently factory processing it to develop laminated clay is to develop a GCL that has enviable sealing characteristics with a greater resistance to geochemical attack and cracking. Since clay liners are buried in the ground as base liners, capping layer or as structural water proofing membrane, they can easily avoid strict quality and performance monitoring being “out of sight, out of mind!”. It is very necessary that barrier design for leachate containment must necessarily be in accordance with legislative requirement Assessment of long term hydraulic conductivities and clay-leachate compatibility assessment is deemed necessary. The derogatory factors affecting the sustainable performance of the bentonite in GCLs placed in difficult construction and hostile chemical environments are discussed. Sustainability concepts incorporated in waste management practice must aim to achieve 100% recycling and fully implement the handling of solid waste in developing countries with relatively lower labour costs.

The ‘peaks and troughs’ of societal violence: Revisiting the actions of Turkish and Kurdish shopkeepers during the 2011 London riots

This article examines an instance of contained violence during the 2011 riots in London, when Turkish and Kurdish ‘shopkeepers’ in Dalston, East London prevented rioters from entering the area. Introducing a ‘peaks’ and ‘troughs’ approach to the sociological study of violence, the article argues that we need to look at the troughs of non-violence in order to understand the peaks of violence and vice-versa. Based on a small-scale empirical study, this article also shows that contrary to the dominant representation of social actors playing fixed roles during social unrest, we found shifting positions and blurred boundaries in the drama of the 2011 riots. The paper demonstrates that the instance of contained violence in Dalston was informed by three types of reverberations. Firstly, we identified anticipatory reverberations, as the shopkeepers were aware of concurrent events elsewhere in London and, as a result, anticipated rioting in Dalston. Secondly, we saw experiential reverberations, as they used their own experience of unrest in Turkey to inform their behaviour. Finally, the representation of the action of the shopkeepers in traditional and social media may have contributed to the containment of violence elsewhere in England, suggesting representational reverberations.

Investigating Links Between Intimacy and Violence in Intensive Psychotherapy

This research examines links between intimacy and violence within the transference relationship of a three year old boy during intensive psychotherapy. Psychoanalytic clinical findings are used to examine triggers to violence that initially appeared to link with moments of emotional warmth. The research uses a retrospective single case study design. The clinical data cover a period of transition in the child's life from being a 'looked after child' in foster care to being adopted. There was a history of early trauma from neglect and domestic abuse. Clinical process notes from supervised sessions were coded using an adapted grounded theory approach to reveal complex interlinking themes of intimacy, violence, Oedipal issues, control and difficulties regulating affect. Data in this study show how intimacy and violence are linked when there is evidence of a separation between the self and the object of intimacy. Explosive violence is triggered by the threat of loss of the object and the rage is, at times directed towards the object of intimacy. The findings of this study support concepts identified by earlier research in the field about the impact of a lack of maternal containment on innate violence, associated struggles with the Oedipal complex and the impact upon the capacity for symbol formation and thinking. However, the research findings challenge Glasser's (1979) theory of the 'core complex' that suggests that intimacy triggers violence. The results of this research indicate that it is the threat to the loss of intimacy as a result of separation from the object that is the trigger to violence. I believe this study may, in a modest way, further understanding about links between violence and intimacy in human relationships. This may help other child psychotherapists be alert to certain dangers when dealing with violence in the therapy room.