British drugs policy: Problematizing the distinction between legal and illegal drugs and the definition of the ‘drugs problem’.

This article draws upon an extensive literature review of the social and medical sciences, official documents and various websites to critically re-evaluate the basis of British drugs policy. The article problematizes the rationale for criminalizing certain substances and questions the distinctions created between legal and illegal drugs; in so doing, the article argues that the definition of the `drugs problem' is the real problem. It shows that the debate on illegal drugs is filled less with factual truths and more with misinformation which creates public fear and provides a questionable basis for public policy. The article questions current thinking regarding the drugs/crime relationship and concludes by exploring some implications for policy and practice.

A new method of measuring plastic limit of fine materials

Index properties such as the liquid limit and plastic limit are widely used to evaluate certain geotechnical parameters of fine-grained soils. Measurement of the liquid limit is a mechanical process, and the possibility of errors occurring during measurement is not significant. However, this is not the case for plastic limit testing, despite the fact that the current method of measurement is embraced by many standards around the world. The method in question relies on a fairly crude procedure known widely as the ‘thread rolling' test, though it has been the subject of much criticism in recent years. It is essential that a new, more reliable method of measuring the plastic limit is developed using a mechanical process that is both consistent and easily reproducible. The work reported in this paper concerns the development of a new device to measure the plastic limit, based on the existing falling cone apparatus. The force required for the test is equivalent to the application of a 54 N fast-static load acting on the existing cone used in liquid limit measurements. The test is complete when the relevant water content of the soil specimen allows the cone to achieve a penetration of 20 mm. The new technique was used to measure the plastic limit of 16 different clays from around the world. The plastic limit measured using the new method identified reasonably well the water content at which the soil phase changes from the plastic to the semi-solid state. Further evaluation was undertaken by conducting plastic limit tests using the new method on selected samples and comparing the results with values reported by local site investigation laboratories. Again, reasonable agreement was found.

Discussion on: Sivakumar, V., Glynn, D., Cairns, P. & Black, J.A. (2009). A new method of measuring plastic limit of fine materials. Géotechnique 59, No. 10, 813-823. by Brendan C. O'Kelly

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