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An integrated open source acoustofluidic platform using surface acoustic waves for biomedical applications
Full text linkSurface acoustic wave (SAW) devices using thin film technology are increasingly used in lab-on-a-chip, point-of-care and a wide variety of biomedical applications, due to their multi-functionalities and low cost. These thin film devices not only have both acoustofluidic sensing and actuation functions, but also have been produced with commonly used semiconductor manufacturing techniques. These allow the acoustic devices to be made on many different substrates, such as aluminium plate and foils, glass, silicon, polymers and plastics, which provide a wide variety of properties enabling many new directions and opening up new applications.
However, acoustic wave technology still requires benchtop lab equipment and experienced operators to utilise these SAW devices because of a lack of hardware integration and autonomous control, resulting in a higher-cost system than the proposed platform. Most SAW interfacing setups are bulky and complex to use. There are currently many studies exploring the uses of mobile phones, cameras and attempting to use open-source electronics to generate and control acoustic waves. In this thesis, we combine SAW microfluidics and sensing with Raspberry-Pi hardware, making a full use of its digital imaging capabilities.
This thesis focuses on integrating surface acoustic wave devices and open-source hardware and software to overcome the challenges with a digitally controlled acoustofluidic platform. The aim of this modular platform is to perform acoustofluidic functions autonomously, such as droplet transportation, mixing, heating and sensing. The basis of this platform is a Raspberry Pi, together with piezoelectric thin films on metallic substrates, 3D printed housing and additional electronics for SAW device control. The setup is then used to demonstrate these functions applied in a variety of biomedical applications, such as disease diagnostics, breathing disorder monitoring and cell culturing
Numerical and experimental study of flow through swelling porous media
Full text linkIn Engineering studies, the flow through porous media is an active subject of research due to its practical applications. The applications include liquid composite moulding techniques, industrial wicks, hygiene products, industrial filtration etc. The computational modelling of flow through porous media is often based on a single-phase or multiphase continuum using Darcy’s law under rigid or swelling conditions. The computational models of fluid flow through porous media help to design and optimise for different engineering applications such as industrial wicks, baby diapers, paper towels, liquid composite moulding processes and heat pipes. The swelling of porous media as a result of liquid absorption by solid particles considerably affects the fluid flow through porous media. As a result, the resistance to fluid flow through porous media increases due to a reduction in the porosity and permeability of porous media.
Hence, the assumption of rigid porous media while developing the computational models is not always correct. The exclusion of swelling effects could lead to a serious error in the predictions from the developed computational model in terms of liquid front positions. Hence the inclusion of swelling effects in computational modelling is crucial and very few works are attempted to model such a flow condition. Further, for the computational modelling of capillary pressure effects, the available multiphase approaches are based on multiple fitting parameters. These parameters need to be measured experimentally or estimated analytically which makes it challenging to implement. The resulting computational model would not predict the liquid front accurately if the correct values of these fitting parameters are not known.
In this study, a novel methodological approach is proposed which allows us to account for the swelling and capillary pressure effects within the porous media. The novel combination of the Finite Volume Method and Volume of Fluid method (FVM-VOF) is used for the first-time to model the liquid absorption and swelling effects within porous media. The proposed methodological framework allows us to model the swelling and capillary pressure effects within porous media precisely with lesser fitting parameters. The use of the volume of fluid method helped to track the liquid-air interface accurately under different working conditions.
The computational models are developed for the different flow scenarios. For the case of flow-through non-absorbing swelling porous media, the modelling approach is first validated against the experimental data obtained from the literature. Further, 2D computational models for the liquid composite moulding process (LCM) are developed and studied. The results demonstrated the effects of permeability and the number of inlet gates on the mould fill times. The proposed methodology is further extended to model the flow through rigid porous media under absorbing conditions. A new analytical model predicting the liquid front locations under draining conditions is proposed. A novel boundary condition allowing us to model the liquid holdup within porous media is proposed. The effect of gravity and the size of the porous domain have a significant effect on the liquid front locations under different values of capillary pressures. The swelling behaviour of the cotton fabric is studied experimentally. A novel method of measurement of porosity changes as a result of swelling is proposed. The experimental results for the porosity changes highlighted the limitations of analytical models which are used to predict the porosity changes. The new correction factors for the existing analytical model are proposed and validated. These factors account for the inter-fibre interactions within the woven fabrics The results related to liquid absorption performance tests revealed that gravitational effects along with the swelling effects considerably affect the liquid absorption performance of fabrics. Finally, the computational models are developed for the case of flow-through swelling porous media under absorbing conditions. The model is developed using the data obtained from experiments. The model is further extended for the case of the flow-through single-layered and multi-layered diapers. It was observed that the changes in the permeability of layers considerably affect the liquid front shapes within the porous media. The outcomes from this study would help researchers to model the swelling and capillary pressure effects accurately with few basic input parameters. The proposed approach has demonstrated its ability to model the applications of forced imbibition in swelling conditions such as Liquid Composite moulding processes used to manufacture composites. The proposed approach can be used to model the applications such as industrial wicks, tissue papers, paper napkins, and hygiene products where flow is dominated by capillary forces and swelling effects in some cases
“Becoming Ahuman: making it desirable to abandon certainty, including certainty of the self, and play in this chaotic situation”
Full text linkTitle: “Becoming Ahuman: making it desirable to abandon certainty, including certainty of the self, and play in this chaotic situation”
Ralph Dorey, Northumbria University, 2020.
This research brings together resonating creative processes from feminist literature, game design, queer gender politics, post-structuralist philosophy, and horror cinema. It uses these to articulate an art practice which is unstable and generative both for the artist during the process of production, and again for the audience.
The PhD output as combined thesis and practice consists of three books, each approaching the question, “How to negotiate art practice as involving processes which are unstable, affective, and resistant to structures?” Each book takes a different position regarding this question and in doing so reshapes it into a sub-question.
The book “Ahuman Desire” explores the question “How to negotiate art practice as involving affects which are at some times indescribable, or overwhelming?”
The book “Ahuman Use” explores the question “How to negotiate art practice as involving salvaged or stolen systems, which are always already breaking down?”
The book “Unknown Lacuna” explores the question “How to negotiate art practice as involving unstable things which can only be seen through what they do?”
Each engages the same question, but with a different emphasis. They are three different attempts and the obvious implication is that these are three of many more potentially attempts.
I have undertaken an extensive literature review across fields which border on art practice. The three books bring together a vast matrix research sources and makes these visible and accessible as an act of care, in keeping with the feminist writing practices which underpin the work. I have developed original methodologies which are used in the different documents across the three books and include the use of speculative fiction, plagiarism, formalist writing strategies, drawing, performance, games, and screenplays as research. As well as using artworks as a site to examine the relationships between different theories of creative process. The rigour of the PhD Output exists not just in the scale of the sources processed and responded too, but in its infrastructural approach which departs from academic norms to resist a cataloguing or hierarchical envelope for the knowledges within.
The PhD Output addresses one of its returning processes of Excess through its form. It is large in scope and shifts responsibility to the reader to navigate this Excess. This demonstrates the affects of anxiety address in many of its documents, before the aforementioned attention to acts of care re-frame this disorder as generative. This mirrors the repeated conceptual and narrative refrain in many documents whereby the horror of the unknown is reorientated to become a creative and dynamic approach to knowledge which does not need to be fixed or enveloped.
The PhD Output aims to support reader engagement based on their desire, rather than through an external economy that ascribes or denies a degree of value based on adherence to pre-existing parameters. This approach is a departure from the common structures of academic research, while still demonstrating critical judgment and original contributions to knowledge. The departure is necessary firstly because of the research questions above, and secondly the commonality of destabilisation in the source materials from feminist writing practices and philosophy, to collaborative games and horror media. Thirdly, the departure enables the specificity of the practice based PhD Output to not just describe processes but to enact them at the reader’s point of encounter with the research.
The primary findings of the research are. The potential for the form of Tabletop Role Playing Game Manuals to inform an art practice when combined with the philosophy of Gilles Deleuze and Félix Guattari. The mutual illumination offered when combined with feminist writing practices or Écriture Féminine. The potential for Écriture Féminine to inform contemporary queer feminist art practices which incorporate the forms of video-games, as well recognising the event of audience encounter with such artworks as a creative one. The use of horror cinema as a means to articulate art practice concerned with affect. The potential of practice-based art research to produce new ways to produce and deliver original research in a dynamic rather than fixed structure.
This research is of value due to its relevance to contemporary practice. This relevance is evidenced by the recent attention to queer indie game design (‘Beyond the Console’, n.d.; Faber, 2019; Humphreys, n.d.; Thaddeus-Johns, 2019; Wallace, 2019), experimental feminist writing practices incorporating speculative fiction (Hedva, 2018; Hval, 2018; Jackson & Leslie, 2018; Waidner, 2019), the divisive concept of “elevated horror” (Carrol, 2019; Crump, 2019; Ehrlich, 2019; Gardner, 2019; Taylor, 2019), and the folding of these into art practice. The research include in-depth analyses of artworks by two artists who have relatively recently received a high international profile (Apexart, 2019; ‘Dark Continent: Semiramis Performance | Arts Council Collection’, n.d.; ‘Porpentine Charity Heartscape’, n.d.; Tate, n.d.) and have not yet been the subject of monographs or a large amount of academic study, particularity within the field of art. The relevance of this research is further supported by the recent publications and events in a overlapping fields (Brazil, 2019; Burrows & O’Sullivan, 2019; Editorial Staff, 2019; Fisher, 2018; ‘Flickering Monstrosities Hyperfiction Reading Group’, 2019; ‘ICA | I, I, I, I, I, I, I, Kathy Acker’, n.d.; Lewis, n.d.; Little, 2019; Pyrne, 2019; Shaw & Reeves-Evison, 2017)
The political and social construction of work in north eastern engineering and shipbuilding, 1880-191820
Full text linkFor fifty years or so at the end of the 19th century the North East of England was an engineering and shipbuilding powerhouse, and a huge mining area. A fast growing population with concomitant infrastructure developments reflected the resulting demand for labour. Yet by 1932 one of the exemplars of this success, Jarrow, was in such dire economic straights that it was described as a “workhouse without walls”.1 The causes of this precipitous decline have been debated, at least in general terms, by historians for years. Was it the failure of owners to adopt more modern management practices, the alleged refusal of the City of London to invest in the UK when they could generate better returns abroad, or a gradual institutional sclerosis paralysing the ability of business to adapt to changed circumstances? This PhD looks at the rise and decline of NE engineering and shipbuilding, focusing on communities rather than class, and looking at what bound them together as well as what kept them apart. This though is not a family history. Through an examination of the political and social construction of work, including case studies of specific workplaces, as well as the ways in which the communities lived, it attempts to provide a more detailed look at ways in which the many thousands of individual choices and decisions made by those community members, which whilst in their own context were rational, in the broader sweep of history created the conditions for long term decline
hospitality in a high-tech, hightouch context: an exploration of the guest-tech-host relationship
Full text linkTechnology has changed the landscape of hospitality in terms of its operation and the guest-host experience. One of the most significant changes is hotel guest empowerment with the use of self-service technologies, blurring the line between guest and host. As technology constantly develops, the interactions and relationships between people also evolve. An area which is currently underexplored within literature is the role of technology within the guest-host relationship. This thesis explores the high-touch, high-tech approach to hospitality service from the perspective of hotel employees and guests. This exploration allows for an understanding of how the relationship between the guest and host is changing.
To understand the relational ties between both guests and hosts, actor network theory and role theory were adopted as a theoretical and methodological lens for the study. To fully explore the guest-host relationship, interviews with both hotel customers and hotel employees were conducted and analysed using thematic analysis. Actor network theory mapping following data collection provides a visualisation of the network that exists between guests, technology, and hosts.
The findings reveal how guests, hosts and technology co exist, collaborate, and navigate the hospitality servicescape. This discussion provides an understanding of guest and host perceptions and preferences of hotel service, and what role technology plays in the interactions. By understanding how the pre-determined roles of the guest and the host are being modified by technology, the researcher posits a guest-tech-host relationship that exists in a high-tech, high-touch hospitality landscape.
The researcher presents the concept of the guest-tech-host relationship as an original contribution to knowledge, adding to the current body of hospitality literature. A guest-tech-host service dynamic is also presented as a conceptual model. The managerial implications of this research will also allow hospitality organisations to further understand the human implications of implementing technologies within their service environments
Characterisation of thermal boundary layers in acceleration
Full text linkThis research explored the thermal boundary layer on flat plates and blunt bodies experiencing moderate to high acceleration and deceleration in stationary air. The primary aim of the research is to evaluate differences in thermal boundary layer profiles and external flow field characteristics caused by moderate to high acceleration and deceleration of flat plates and blunt bodies with the corresponding steady-state profiles at the same instantaneous Mach numbers.
Using two-dimensional numerical models of flat plates and blunt bodies, the emphasis is on subsonic and hypersonic Mach numbers. OpenFoam is employed as the computational fluid dynamics software, and a custom solver for handling the unsteady conditions during acceleration and deceleration was developed based on the non-inertial conservation equations for mass, momentum, and energy derived in this research.
In subsonic cases, steady state simulations were conducted at velocities ranging from 10m=s to 70m=s, whereas hypersonic cases were simulated at Mach numbers ranging from 4 to 7. Using unsteady simulations, the flat plate and blunt body were accelerated at moderate (10g) to high (100000g) acceleration magnitudes, beginning at the lower velocity, and decelerated at moderate (0-10g) to high (-100000g) deceleration magnitudes, beginning at the higher velocity, over the same range of velocities. Flat plates were set at different wall temperature conditions to confirm the generalisability of thermal boundary layer profiles for subsonic and hypersonic regimes.
During acceleration at subsonic speeds, the skin friction coefficient and Nusselt numbers were found to be greater than their respective steady state profiles at the same velocities, but the opposite was true during deceleration at subsonic velocities. These differences were explained by the non-inertial thermal boundary layer equations derived in the present research and the response of the thermal boundary layer classified as weak (Type I), moderate (Type II), and strong (Type III). Differences between the unsteady and steady thermal boundary layer characteristics at subsonic speeds were found to be a function of the favourable or adverse pressure gradient exerted on the boundary layer by the external flow. Minimal variations were identified between the steady and unsteady thermal boundary layer characteristics in the hypersonic regime, and only a weak favourable pressure gradient (Type I) was observed. Moreover, acceleration/deceleration dependent behaviour of the bow shock was only detected at high acceleration magnitudes above the existing range of applications
Relational approaches to designing social innovation: insights from Europe and Asia Pacific contexts
Full text linkThis qualitative investigation explores different dynamics of interpersonal relationships in processes of designing social innovation (DSI). Combining practice-led research in Italy and online with insights from practitioners working in different contexts in the Asia Pacific region, it nuances the understanding of relationships and their significance for DSI processes.
This research uses Kasulis’s Intimacy or Integrity framework (2002) as a lens to observe both the researcher’s experience and that of practitioners working in different contexts and cultures. Reflexive thematic analysis is used to analyse the practitioners’ insights, while specific dynamics in the researcher’s practice are explored through reflective practice, dialogue and relationship with colleagues and collaborators, leading to the identification of three themes. These are organised in a Framework for Relational Literacy.
The first theme highlights the importance of building a system of reciprocity between those involved in a DSI initiative. The concept of reciprocity is explored through the identification of different dynamics of generosity in DSI initiatives, their benefits, and the risks connected to them. The second theme explores the establishment and maintenance of mutuality in relationships through core features of mutual trust and psychological safety; mutual respect and mutual learning; role-taking and power dynamics. The third theme nuances the construction of a shared relational identity in DSI processes. It examines tensions and overlaps between preserving individuality and prioritising reciprocal attunement, and discusses their influence on the designers’ identity in DSI processes.
The research findings depict designing social innovation as an intricate and complex process. They question solutions-focused, design-centric approaches to social innovation and problematise the emphasis on methods and tactics over relationships, as it can marginalise or erase contextual specificities and the political dimension of designing social innovation. This study supports practitioners in their transition towards intimate and relational ways of understanding, doing, and accounting for DSI processes, enabling DSI theory and practice to welcome a stronger plurality
Do counterfeits only affect luxury brands that are heavily counterfeited?
Full text linkCounterfeit trade has been growing incessantly every year and due to its impact on legitimate brands, it has garnered the attention of researchers, policy makers, and brand managers. Research has largely focussed on the direct influence of counterfeits on original luxury brands and has ignored the potential impact of counterfeits on non-luxury brands. Luxury and counterfeit luxury consumption is particularly prominent during status signalling amongst social classes. Literature on socioeconomic status (SES) reveals that self-discrepancies arise from social comparisons, leading consumers to seek compensatory consumption to alleviate these discrepancies through luxury, counterfeit luxury, and non-luxury brands. Therefore, it is crucial to include non-luxury brands in the debate of impact of counterfeits on original brands.
The present research aims to bridge this research gap by investigating the impact of counterfeits on non-luxury brands, beyond luxury brands. Specifically, it explores the substitution mechanism between the three brand substitutes – counterfeit luxury, original luxury, and non-luxury brands. This research is delineated in accordance with SES, brand substitution, and symbolic self-completion as a compensatory consumption strategy to address the self-discrepancies generated by SES. To achieve this aim, it adopted a mixed methods approach which involved a netnographic study, followed by in-depth interviews with 26 consumers based in the UK.
This research provides a comprehensive understanding of the impact of counterfeits on original luxury brands and beyond. In finding that non-luxury brands are also substituted by counterfeit luxury; this research contributes to the counterfeit consumption literature by adding non-luxury brands to the debate related to the concurrent ownership of counterfeits and original luxury brands. Using thematic content analysis, this research identifies four consumer types based on their childhood SES, adulthood SES, and emotional wellbeing (EW) factors and demonstrates how these factors shape the brand substitution between the three brand types (i.e., counterfeit luxury, original luxury, and non-luxury brands). In doing so, this research contributes to the consumer taxonomies by Han et al. (2010) and Wall & Large (2010) that have identified counterfeit and luxury consumption based on wealth and status needs. By unearthing the underlying causes of brand substitution in counterfeit consumption through compensation strategy, it extends the role of symbolic self-completion theory, dissociation, and self-verification theory to counterfeit consumption literature and compensation strategy theory