A politicised epistemology and its effects upon universities and their management of societal ontology

In recent years the universities have changed from pre-enlightenment "protectors" of societal knowledge to typically modern "business" orientated bureaucracies. It is argued that as a consequence, their status has also changed from one of independent "observer" into that of "product producer"; driven particularly by their newly adopted managerialistic principles, aimed at making them more "business" orientated. This has been fuelled by the domination of a scientistic (Positivist) epistemology throughout the university sector, which emerged from an important philosophical debate, in the sixties, between Kuhn and Popper. Establishing facticity, based upon scientistic methodology, in research as supreme; it allowed for a marriage of convenience between the managerialistic ambitions of the new elite and the worldly theory it purported, as a self-fulfilling justification and prophecy of their actions. Debate in this area has been centred upon the practicalities of managing such a change and its consequences in terms of organisation and management efficiencies. Discussion regarding longer-term effects of whether such a change in the universities, driven in particular by their business schools and senior management, might have a more fundamental impact upon the way we theorise and think about ourselves, is rarely covered. It is contended that such omission is misplaced. The universities' traditional role in society as guardians of our ontological theorectics is being downgraded by increasing demands for them, from government bodies and the like, to behave akin to profit making organisations. This thesis is contending, therefore, that as a consequence of university management search for greater efficiencies, the epistemological frameworks for research, and subsequent theorectics, in the universities have become politicised. It is argued that eventually this will affect society's ontological frameworks and hence change the way we, as individuals, regard our reality. Central to this, is the premise that given the dominant scientistic method, alluded to above, is tainted by political intrusion, it would be inappropriate to use it as a method of analysis. However, it is also contended that constructivist ethnomedology is similarly, and ultimately, dependent upon rationo¬factual research and therefore is inappropriate. With the use of a negative dialectic, instituted by early Frankfurt School discussion, this work, therefore, seeks to establish a new facticity independent, universal theorectic based upon proto-epistemological states. The aim is to lay bare the corruptible nature of the relationship between politicised epistemology and its consequential ontological state and thus demonstrate the potentiality of the danger facing our universities and society

Experimental observations of mechanical dilation at the onset of gas flow in Callovo-Oxfordian claystone

Understanding the mechanisms controlling the advective movement of gas and its potential impact on a geological disposal facility (GDF) for radioactive waste is important to performance assessment. In a clay-based GDF, four primary phenomenological models can be defined to describe gas flow: (i) diffusion and/or solution within interstitial water; (ii) visco-capillary (or two-phase) flow in the original porosity of the fabric; (iii) flow along localized dilatant pathways (micro-fissuring); and (iv) gas fracturing of the rock. To investigate which mechanism(s) control the movement of gas, two independent experimental studies on Callovo-Oxfordian claystone (COx) have been undertaken at the British Geological Survey (BGS) and LAEGO–ENSG Nancy (LAEGO). The study conducted at BGS used a triaxial apparatus specifically designed to resolve very small volumetric (axial and radial) strains potentially associated with the onset of gas flow. The LAEGO study utilized a triaxial setup with axial and radial strains measured by strain gauges glued to the sample. Both studies were conducted on COx at in situ stresses representative of the Bure Underground Research Laboratory (URL), with flux and pressure of gas and water carefully monitored throughout long-duration experiments. A four-stage model has been postulated to explain the experimental results. Stage 1: gas enters at the gas entry pressure. Gas propagation is along dilatant pathways that exploit the pore network of the material. Around each pathway the fabric compresses, which may lead to localized movement of water away from the pathways. Stage 2: the dendriticflow path network has reached the mid-plane of the sample, resulting in acceleration of the observed radial strain. During this stage, outflow from the sample also develops. Stage 3: gas has reached the backpressure end of the sample with end-to-end movement of gas. Dilation continues, indicating that gas pathway numbers have increased. Stage 4: gas-fracturing occurs with a significant tensile fracture forming, resulting in failure of the sample. Both studies clearly showed that as gas started to move through the COx, the sample underwent mechanical dilation (i.e. an increase in sample volume). Under in situ conditions, the onset of dilation (micro-fissuring) is a necessary precursor for the advective movement of gas

Gas migration in pre-compacted bentonite under elevated pore-water pressure conditions

Pre-compacted bentonite has long been proposed as a primary component of an engineered barrier system for the safe geological disposal of radioactive waste. Selection of properties such as the clay composition, compaction-state and clay-to-sand ratio varies in different disposal concepts. However, a sound understanding of the gas transport properties of the barrier material is often considered a necessary part of safety case development for a geological disposal facility. In this study, results are presented from two gas injection experiments conducted in Mx80 bentonite, under elevated pore-water pressure conditions. Test observations indicate that the conditions necessary for gas to enter this material are remarkably consistent, irrespective of the applied water pressure. As expected, an association is noted between the total stress experienced by the clay and the gas pressure at the moment of entry. Gas migration is interpreted as occurring by the formation and propagation of dilatant pathways within the bentonite. Local pore-pressure and stress measurements indicate that significant reworking of the clay can occur, resulting in meta-stable episodes of ‘pressure-cycling’, as gas seeks a stable escape pathway. These findings demonstrate the potential for ‘phases’ of pathway development and propagation within the buffer, resulting in successive migration episodes over the repository lifetime. Experiments also show the potential for gas entry into the buffer to occur as a result of declining pore-water pressure conditions. As such, the influence of significant deviations from hydrostatic conditions (for example, resulting from glacial loading) should not be neglected when considering gas interaction with the buffer over long timescales

Observations of pore pressure in clay-rich materials; implications for the concept of effective stress applied to unconventional hydrocarbons

The concept of effective stress is a well-established relationship where the stress acting on a rock can be viewed as the total stress minus the pore water pressure. In clay-rich rocks this relationship has been seen to be imperfect and a Biot coefficient is added to account for the material properties of the clay matrix. Large, stable pressure differentials and gradients were observed in several argillaceous materials during water and gas injection testing for a number of experimental geometries, including triaxial (Callovo-Oxfordian claystone), shear (kaolinite and Opalinus Clay) and full-scale testing (bentonite). Pore-pressure during water injection appeared to be evenly distributed on the sample scale, whereas in full-scale demonstration a complex distribution was seen, which may partly be due to hydraulic disequilibrium. During gas injection testing all observations suggested that transport was predominantly by dilatancy flow and the formation of micro-fissures. This led to localized pore pressure variations and a complex temporally and spatially varying pore pressure distribution. Isolated pockets of increased gas pressure could be seen to be stable. The nature of pore-pressure distribution, both hydraulic and gaseous, and the stability of pore pressure differentials means that the description of a meaningful average pore pressure was difficult and thus the use of effective stress with a single χ value might misrepresent local stresses within the rock. Localized deformation in the formation of dilatant pathways was dominated by the local gas pressure and not the bulk pore pressure. Therefore the law of effective stress on the micro-scale will be valid, whereas on a bulk scale could lead to errors in model predictions. This also has implications on the release of gas from shale due to the localized influence of stress around a fracture. Flow along fractures was localized with only a proportion of the fracture surface playing a part in both water and gas flow

Gas transport properties through intact and fractured Callovo-Oxfordian mudstones

A series of controlled water and gas experiments was undertaken on samples of Callovo-Oxfordian (COx) mudstone using a synthetic fluid and helium gas. Data from this study demonstrate that the advective movement of gas through COx is accompanied by dilation of the original fabric (i.e. the formation of pressure-induced microfissures) at gas pressures significantly below that of the minimum principal stress. Flow occurs through a local network of unstable pathways, the properties of which vary temporally and spatially within the mudstone. The coupling of variables results in the development of significant time-dependent effects affecting many aspects of COx behaviour, from the gas breakthrough time to the control of deformation processes. Variations in gas entry, breakthrough and steady-state pressures may result from the arbitrary nature of the flow pathways and/or microstructural heterogeneity. Under these conditions, the data suggest that gas flow is along pressure-induced preferential pathways, where permeability is a dependent variable related to the number, width and aperture distributions of these features. This has important implications for modelling gas migration through low permeability, clay-rich materials

High-entropy high-hardness metal carbides discovered by entropy descriptors

High-entropy materials have attracted considerable interest due to the combination of useful properties and promising applications. Predicting their formation remains the major hindrance to the discovery of new systems. Here we propose a descriptor - entropy forming ability - for addressing synthesizability from first principles. The formalism, based on the energy distribution spectrum of randomized calculations, captures the accessibility of equally-sampled states near the ground state and quantifies configurational disorder capable of stabilizing high-entropy homogeneous phases. The methodology is applied to disordered refractory 5-metal carbides - promising candidates for high-hardness applications. The descriptor correctly predicts the ease with which compositions can be experimentally synthesized as rock-salt high-entropy homogeneous phases, validating the ansatz, and in some cases, going beyond intuition. Several of these materials exhibit hardness up to 50% higher than rule of mixtures estimations. The entropy descriptor method has the potential to accelerate the search for high-entropy systems by rationally combining first principles with experimental synthesis and characterization.Comment: 12 pages, 2 figure

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

Gas network development in a precompacted bentonite experiment: evidence of generation and evolution

In a deep geological disposal facility for radioactive waste, precompacted bentonite is proposed as a sealing material for the isolation of boreholes, disposal galleries and deposition holes. The advective movement of repository gas in bentonite has been linked to the development of new porosity and propagation of dilatant pathways. For the first time we present a detailed analysis of stress field data during the generation and evolution of a gas network. A new experimental dataset, from a highly instrumented test, clearly shows the strong coupling between stress, gas pressure and flow in bentonite. Multiple discrete propagation events are observed, demonstrating spatial variability and time-dependency as permeability within the clay develops. Analysis of the stress data before, during and after gas entry indicates a heterogeneous stress field initially develops, resulting from the development of these pathways. The flow network is dynamic and continues to spatially evolve after gas entry, such that permeability under these conditions must be time-dependent in nature. Perturbation of the stress field is significant before all major gas outflow events, presumably resulting from the requirement to propagate an effective gas network before outflow is possible. In contrast, no major flow perturbations are detected which did not correlate with fluctuations in the stress field. The controls on the distribution and geometry of the resulting flow network are unclear, as well as its long-term evolution and stability. These will be beneficial in the assessment of gas pressure evolution as part of safety case development