Effects of high temperatures on soil properties : lessons to share from smouldering remediation experience

Aggressive, high-temperature contaminant remediation processes such as smouldering remediation are growing in popularity as technical knowledge of their capabilities becomes more widespread. Smouldering remediation is most aggressive of these processes and exposes soils to temperatures across the range of 500-1000 oC for hours to days, displacing water and destroying in excess of 99.9% of contaminant mass. The high temperatures and aggressive chemical reactions result in significant changes to the soil properties, particularly at the particle surface. Shifts in soil geochemistry, mineralogy, and structure are observed. Micro computed tomography shows that grain surfaces become significantly smoother after remediation. The changes are more extensive than initial mineralogy testing had suggested. Increased smoothness affects grain-grain and grain-water interactions and may explain some of the dynamic changes in infiltration, permeability, cohesiveness, and strength that have been observed in soils after smouldering remediation. Understanding these effects is essential to link micro-scale changes to macro-scale behaviour and develop a holistic approach to contaminated soil remediation and reuse. Important analogies can be drawn to the effects of fires on soil properties

The Power Hour of Writing: An empirical evaluation of our online writing community

The “Power Hour of Writing” is an institution-led approach which brings together staff and postgraduate research students in a community that encourages participants to write regularly as part of their academic practice, helping to develop sustainable habits. This research into the “Power Hour of Writing” combines analysis of participant numbers with qualitative analysis of free text responses from online surveys taken at three different time points. Three themes emerged and were evident across all three surveys, independent of their time point: The importance of community; making writing a legitimate part of people’s everyday work; and accountability, which is built into the structure of the “Power Hour Of Writing”. Our research indicates that regular, short timeslots for writing can have a valuable impact on staff and postgraduate researchers. Not only did this intervention help build the community at a time while people were working even more in isolation due to the pandemic, but it also highlighted to participants that protecting time for writing benefits their work

Poetic reflexivity. Walking to inform poetry as a response to disembodied research during a pandemic

Poetry can be used as an adjunct to interviews in social science to build relationships and share meaning to create an artefact that provokes dialogue between the researcher and research study participants. Describing the sensemaking of researcher identity as a narrative walk, Datawalking is extended as an embodied post-data qualitative research method to inform autoethnography and poetry. These methods articulate the ways to support researcher wellbeing to counter the loneliness of remote research which can be heightened by external factors such as the lockdowns of the COVID-19 pandemic. We illustrate two poems used alongside phenomenological interviewing to inform reflexive knowledge in educational research. By exploring poetic techniques including meter, alliteration, and enjambment we seek to advance the understanding of evocative autoethnography as a polyphonic form of expressive scholarship to instantiate dialogue in social research. This approach, centred on identity and praxis, has uses for organisational studies in education

Bentonite permeability at elevated temperature

Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeabilit