A new approach in landfill liner design which combines hydraulic containment of leachate with contaminant attenuation to improve the performance of these environmental control systems at landfills is described. The idea is to re-use readily available industrial waste residues (construction and biomass waste) as additives for natural clay liners, wherein the additives have specific properties which enhance the attenuation of contaminants by the mixture. The aim is to (1) evaluate the contaminant attenuation capacity of these mixtures, (2) develop design guidelines to construct liners for waste containment systems and similar applications, and (3) interpret their performance using numerical modelling. This is evaluated in permeation studies using a geotechnical centrifuge, which enables the performance of liner compositions to be tested for representive time-scales (100 years), pressures and temperatures at realistic experimental time-scales of days-weeks in the laboratory. The permeation experiments include liner compositions flushed with leachate to deduce contaminant transport and attenuation mechanisms, followed by rainwater to assess the potential for release of attenuated contaminants. This experimental methodology is illustrated with depth profiles from permeation studies conducted on different clay-additive compositions. The concept will be applicable for liner design at other waste disposal facilities and is a timely improvement which addresses the problem of managing large quantities of industrial residues. Instead of disposal these can be recycled as an additive in host clay to construct these liners, thus conserving natural resources (clay) and reducing construction costs. It also provides an effective and more environmentally sustainable basis to reduce risks from leachate leakage.

A summary overview of 5 years working with a small-scale educational centrifuge at the University of Sheffield is presented. Various geotechnical design problems have been successfully performed throughout this period, including slope stability, bearing capacity failure and tunnelling. The opportunity to experimentally explore the theoretical content taught in lectures has had a positive impact on student learning in the undergraduate curriculum. The authors advocate there is an immediate need for greater adoption of experimental based observation/demonstration, either conducted at 1g or Ng, to be embedded within the geotechnical undergraduate curriculum to enrich and deepen the student learning experience of geotechnical system performance.

Innovator in perinatal mental health Diana Riley was a key figure in obstetric liaison psychiatry and perinatal mental health. She researched and published widely over 36 years, including works for health professionals and lay readers on postnatal depression and drug addiction in pregnancy.

Thermoacoustic phenomena, involving the generation of sound by fluctuating heat addition have been studied for over two centuries. They are most familiar in the form of such laboratory devices as the Sondhaus tube and the Rijke tube and in the destructive instabilities that can occur in combustion systems. Now, Albert Migliori and Greg Swift at the Los Alamos National Laboratory in New Mexico have put these phenomena to practical use in a novel thermoacoustic engine (Appl. Phys. Lett. 1988 53 355).