Dead-end filtration of yeast suspensions: correlating specific resistance and flux data using artificial neural networks

The specific cake resistance in dead-end filtration is a complex function of suspension properties and operating conditions. In this study, the specific resistance of resuspended dried bakers yeast suspensions was measured in a series of 150 experiments covering a range of pressures, cell concentrations, pHs, ionic strengths and membrane resistances. The specific resistance was found to increase linearly with pressure and exhibited a complex dependence on pH and ionic strength. The specific resistance data were correlated using an artificial neural network containing a single hidden layer with nine neurons employing the sigmoidal activation function. The network was trained with 104 training points, 13 validation points and 33 test points. Excellent agreement was obtained between the neural network and the test data with average errors of less than 10%. In addition, a network was trained for prediction of the filtrate flux directly from the system inputs and this approach is easily extended to crossflow filtration by adding inputs such as the crossflow velocity and channel height. An attempt was made to interpret the network weights for both the specific resistance and flux networks. The effective contribution of each input to the system output was computed in each case and showed trends that were as expected. Although network weights, and consequently the computed effect of each parameter, is different each time a network is changed (depending on the initial weights used in the training process), the variation was low enough for information contained in the network to be interpreted in a meaningful way

The ideal of the modern subject? Exploring the limits of the 2004 Irish citizenship referendum debate

This thesis explores the limitations of how political subjectivity is conceptualized in existing analysis of the 2004 Irish Citizenship Referendum. By approaching this analysis through the work of R.B.J. Walker and his notion of the constitutive subject of sovereign politics, what is highlighted is how its existing statist starting point for theorizing political subjectivity fails to allow for an understanding of how other types of subjectivity, which cannot be defined in terms of a sovereign binary, might also need to be theorized in respect of the question of migration. The ambiguous subjectivity of Irish citizen children born to migrant parents – as those neither ‘included in’ or ‘excluded from’ the state but in-between both positions – is pointed to in this thesis as an example of the type of complex subjectivity which is denied a place in the ‘politics’ of the 2004 Irish Citizenship Referendum, as currently theorized. Drawing on the work of Julia Kristeva, the thesis considers what an alternative framework for exploring citizenship outside of the dominant framing of sovereign subjectivity, would look like. By approaching the question of citizenship from the perspective of her work, this thesis shows how political subjectivity can also be understood as embodied in experiences of relative and contingent spacetime of ‘being’. It uses the metaphor of ‘trace’ to conceptualize these alternative spatiotemporal experiences. As such the thesis contributes to our understanding of the politics of dominant ‘critical’ citizenship scholarship; the impact of migration on conceptions of belonging; and to broader theoretical attempts to recognize how political subjectivity is experienced outside of a statist political discourse. It concludes that existing analysis of the 2004 Irish Citizenship Referendum is limited by its inability to theorize political subjectivity outside of a specific conception of space as independent of its physical content and of time as linear and progressive

'Unfamiliar Acts of Citizenship: Cultural Practices, Sensory Engagement and Ambiguity’

This chapter explores unfamiliar acts of citizenship located in cultural enactment(s). It unpacks what is unfamiliar here and the implications of focusing on cultural practices for how we can better understand citizenship as a challenge and re-enactment. It points to the indirect nature of cultural acts which are engaged in through embodied and affective meaning rather than as direct statements/declarations of discontent. I look at how these are mobilised within, and start from, an indeterminate and ambiguous space of inclusion and exclusion, rather than from a starting point of familiar political struggle which end up at questions of ambiguity and indeterminacy. Drawing on decolonial theory, I argue that they therefore force us to think about the unfamiliar (not yet recognised) ways we have yet to imagine and understand that citizenship struggles may take place. It uses the example of vernacular language as a cultural act to consider this in detail

Decolonising and the Aesthetic Turn in International Studies: Border Thinking, Co-creation and Voice

The aesthetic turn (AT) in International Studies stresses the ongoing task of marshalling non-western insights to better explore the agency of the globally marginalised in discourses about representability. Decolonial literature also calls specifically for more understanding of relationality and co-creativity underpinning agency and voice in global politics. Building on this decolonialising challenge, this article embeds a focus on ‘ordinary language use’ within a ‘decolonial orientation’ to open up complexities around the politics of representability. It specifically employs the concept of ‘border thinking’ by Walter Mignolo; and centres struggles in language by Gloria Anzaldúa as well as in the vernacular language ‘Verlan’ (as used by working-class racially marginalised people in France) to think ‘from’ the border. Highlighting how language works across (not just within) different registers and forms, the categories of ‘non-standard’ and ‘standard’, ‘domination’ and ‘resistance’ are destabilised. This provides the basis for re-centring Othered voices within a more relational co-creative ontology, by making the entanglement of discipline and resistance a space to think modernity from, rather than a space of interruption into modernity