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Airliners carry substantial amounts of fuel inside their wing tanks, causing liquid-structure interaction effects that are not fully understood. Whilst often modelled as frozen mass, the fuel inside wing-integrated tanks can also interact violently with the wing structure, leading to phenomena that may be exploited as a means of passively reducing gust loads and increasing the net damping. Specific to the out-of-plane bending motion of flexible wings, the main liquid excitation direction is vertical and the wing amplitudes can exceed the fuel tank height. The primary aim of this thesis is to analyse the nonlinear dynamic interactions between aircraft wings and the fuel contained inside their built-in tanks following discrete gust-type excitation. To achieve this aim, four experimental campaigns were carried out with gradually increasing complexity and three sloshing numerical models were investigated. The vertical sloshing interaction typical of aircraft wings was isolated as a single degree of freedom and studied under transient liquid-structure coupled conditions and also harmonic excitation. A novel 3m long wing demonstrator with a semi-transparent fuel tank allowing for flow observation was designed, manufactured, and tested. Multiple numerical approaches based on sloshing equivalent mechanical formulations gave good agreement with the experiments. The dependency of damping on filling level and amplitude of excitation was investigated under various excitation conditions with a focus on the highly nonlinear large-amplitude regimes. The optimal filling level where the sloshing damping effect is maximized under vertical excitation was found to be 50% and also the existence of a damping saturation amplitude was demonstrated and systematically evaluated. In-depth sloshing hysteresis cycle analysis showed the relationship between the liquid sloshing patterns and the amplitude and frequency-dependent induced damping. These insights were used to further understand the effects observed in the realistic scaled wing demonstrator. Damping variations similar to those observed in the simpler systems were noted in terms of filling level and excitation amplitude, with particularities due to the added complexity of wings, such as the nonuniform spanwise tank amplitude, tank geometry, or richer frequency content. The spanwise distribution of fuel influences the damping significantly via the varying sloshing root moment arm and local vertical acceleration. The tank baffles were found to have an effect only via their spanwise compartmentalization of the fuel. In the most realistic case considered, with representative baffle geometry and positive dihedral, a damping ratio increase of 2.33% critical damping on top of the structural damping was observed due to violent sloshing immediately after step release. The findings presented here are significant as they indicate means of exploiting the already existing fuel inside wing tanks to increase the net structural damping. The extensive experimental data available is also valuable for the liquid sloshing community for further developments of high and low-fidelity numerical models.

A model complex of dysprosium, Dy(N2O2C7H11)3 (Dy2) was built by successive capping of the peripheral aromatic ring of a butterfly-shaped dysprosium complex of a schiff base ligand, Dy(N4O5C14H11)3 (Dy1). The structural modifications were carried out in order to investigate the effect of the chemical surroundings like aromaticity on the observation of single-molecule magnet (SMM) behaviour in a lanthanide-based complex (Dy1). Experimental techniques were combined with theoretical tools to investigate the dynamics of magnetic properties of the Dy1 and compared with the theoretical results for Dy2 to gain insight on the contribution of covalency, crystal field effect and the role of aromaticity in stabilizing the excited magnetic levels of a single-molecule magnet. Dy1 showed frequency-dependent slow magnetic relaxation characteristics of a single-molecule magnet with and without applied dc field and a blocking temperature of about 8 K. The obtained results showed that despite f−electrons having weak interactions with ligand field, it is possible to tune the magnetic properties of lanthanide-based complexes using ring currents, control of covalency and peripheral ligand substitution. Furthermore, di-nuclear acetate bridged lanthanide complexes with two different structural motifs, Er1 = [Er(CH3COO)(CH3COO)2(H2O)2]2 · 4H2O and [Ln(CH3COO)(CH3COO)(CH3COO)(H2O)CH3COOH]2 · 2CH3COOH (Ln = Er (Er2), Y0.8Er0.2 (Er3)) were characterised. The solvent effects on the structure, electronic and magnetic properties were studied by experiments and theoretical methods. The tetraacetate-bridged erbium (Er2) showed a shorter intra-molecular Er - Er distance of 3.878 Å compared to the doubly-bridged counterpart (Er1) with Er - Er intra-molecular separation of 4.152 Å. Er2 exhibited weak ferromagnetic ordering at very low temperature in the dc magnetic measurement due to the short proximity of the Er centres. A field-induced slow magnetic relaxation for spin reversal characteristics of single-molecule magnet behaviour with relaxation dynamics dominated by Orbach process was observed for Er2. Er1 showed very fast slow magnetic relaxation dominated by quantum tunnelling of magnetization as evidenced in the Cole-Cole plot and the observed plateau in the susceptibility curve. The role of inter-molecular interactions between Er centres was investigated using yttrium diluted sample (Er3). The enhanced magnetic property of Er2 and Er3 over Er1 is attributed to the structural changes accompanying the choice of synthetic solvents used as well as the stronger interactions between Er and oxygen donor atoms of the acetate/acetic acid over that of water molecule as ligands. The present study presents an interesting result on solvent effects in the design of single-molecule magnets. In addition to the peripheral, aromatic, solvent effect and accompanying lanthanide-lanthanide coupling investigated, the role of hetero-metallic Pd-Ln bonding interaction was investigated using a set of tetranuclear acetate-bridged palladium-lanthanide complexes of the formula [Pd2Ln2(H2O)2(AcO)10] · 2AcOH (AcO = CH3COO- , Ln = Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm and Yb) by theoretical means and compared with experimental results for the lanthanide series to establish an interesting alternating trend in the observation of slow magnetic relaxation between Kramers and non-Kramers ions along the series. The role of axial perturbation, electron-cloud distortion and utility of metal as a ligand to upset the electronic properties of lanthanide complexes and their implication to the observation of slow magnetic relaxation were investigated. Results showed that transition metal-lanthanide bonding interaction presents a unique way to control the ligand field of lanthanide at varying degrees while confirming the role of rigidity in SMM design.

In recent years there has been an increased interest on flexible fluid-structure interaction problems with applications to flow control (reduction of drag and lift fluctuations) and energy harvesting. Particularly, studies have suggested that a hairy coating (poroelastic coating) may help reduce drag and lift fluctuations of a bluff body (cylinder) by around 15% and 40%, respectively. However, these studies have focused on two-dimensional setups, therefore real effects such as three-dimensional vortex shedding in the wake of a cylinder have not been considered. For instance, preliminary experiments carried out in a wind tunnel revealed that the motions of a single filament in the wake of a cylinder are complex due to the influence of the cylinder wake flow and the outer crossflow impinging on the hanging filament (sagged due to gravity). For this reason, this work was set to study experimentally the fundamental behaviour of filaments alone, hanging from a vertical support tube (i.e. not attached to a bluff body). This simple configuration is ideal to analyse the fundamental dynamics of flexible filaments in flow and provide insights for future investigations of hairy coatings. Noteworthy, the filaments hanging in crossflow were free to move in three dimensions, in contrast to the previously existent studies which come from two-dimensional studies, and thus provides unprecedented data valuable for validating fluid-structure interaction simulation codes. At low wind speeds the filaments bent and remained in static equilibrium, similar to the reconfiguration of plants. Beyond this condition, at a certain wind speed, the filaments started to vibrate and in certain cases entered into large-amplitude three-dimensional flutter motions which became more complicated as the wind speed was further increased. Through the use of stereoscopic non-contact high-speed imaging, hotwire anemometry, smoke visualizations and the recourse to linear and nonlinear time-series analysis techniques, the full range of filament behaviours were studied in detail. In particular, the results from this research provided unprecedented data and empirical correlations for the filament static reconfiguration and fluid loading at previously unexplored conditions. Also, the fluid mechanisms responsible for the onset of filament motion were investigated. Additionally, the vortex shedding from reconfigured filaments was for the first time experimentally studied and characterized. This work also provided the first documentation of the three-dimensional flutter motions of filaments, and the effects of turbulence intensity and filament attachment angle on the filaments flapping motions dynamics. Finally, the experimental methodologies (data acquisition, image processing and time-series analyses of motion) developed during this research were also applied for studying other fluid-structure interactions problems: the flow-induced vibration of cantilever rods in axial flow for nuclear reactor applications, and the dynamics of inverted flags for energy harvesting applications.

Recent trends in energy production have led to a renewed interest in improving grid level energy storage solutions. Flywheel energy storage is an attractive option for grid level storage, however, it suffers from high parasitic loss. This study investigates the extent to which passive diamagnetic bearings, a form of electromagnetic bearing, can help reduce this parasitic loss. Such bearings require three main components: a weight compensation mechanism (lifter-floater), a stabilizing mechanism and an electrical machine. This study makes use of a new radial modification of an existing linear multi-plattered diamagnetic bearing. Here a prototype is built and analytical expressions derived for each of the three main components. These expressions provide a method of estimating displacements, fields, forces, energy and stiffness in the radial diamagnetic bearing. The built prototype solution is found to lift a 30 [g] mass using six diamagnetic platters for stabilization (between ring magnets) with a disc lifter and spherical floater for weight compensation. The relationship between mass and number of platters was found to be linear, suggesting that, up to a point, increases in mass are likely possible and indicating that significant potential exists for these bearings where high stiffness is not needed – for instance in flywheel energy storage. The study examines methods of reducing bearing (parasitic) losses and demonstrates that losses occur in three main forms during idling: air-friction losses, electrical machine losses, stabilizing machine losses. Low speed (158 [rpm]) air-friction losses are found to be the dominant loss at 0.1 [W/m3]. The focus of this study, however, is on loss contributions resulting from the bearing’s electrical machine and stabilizing machine. Stabilizing machine losses are found to be very low at: 1 × 10−6 [W/m3] – this leaves electrical machine losses as the dominant loss. Such electrical machine losses are analysed and divided into eddy current loss and hysteresis loss. Two components of hysteresis loss are remanent field related cogging loss and remagetization loss. Eddy current losses in silicon steel laminations in an electrical machine are quite high, especially at high speeds, with losses in the order of 1 × 105 [W/m3]. Noting the further high cost of producing single unit quantities of custom lamination-based electrical machine prototypes, this high loss prompts a look at potentially lower cost ferrite materials for building these machines. A commercial sample of soft magnetite ferrite is shown to have equivalent eddy current losses of roughly 1 × 10−13 [W/m3]. The study notes that micro-structured magnetite has significant hysteresis loss. Such loss is in the order of 1 × 10−3 [W/m3] when referring to both remanence related cogging and remagnetization. This study, thus, extends its examination of loss to nano-structured magnetite. Magnetite nano-particles have shown superparamagnetic (no hysteresis) behaviour that promises the elimination of hysteresis losses. A co-precipitation route to the synthesis of these nano-particles is examined. A detailed examination involving a series of 31 experiments is shown to demonstrate only two pathways providing close-to-superparamagnetic behaviour. After characterization by Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD), Superconducting Quantum Interference Device (SQUID) and crude colorimetry, the lowest coercivity and remanence found in any given sample falls at −0.17 [Oe] (below error) and 0.00165 [emu/g] respectively. These critical points can be used to estimate hysteresis related power loss, however, to produce bulk ferrite a method of sintering or bonding synthesized powder is needed. A microwave sintering solution promises to preserve nano-structure when taking synthesized powders to bulk material. A set of proof-of-concept experiments provide the ground work for proposing a future microwave sintering approach to such bulk material production. The study uses critical points measured by way of SEM, XRD, SQUID characterization (e.g. remanence and coercivity) to implement a modified Jiles-Atherton model for hysteresis curve fitting. The critical points and curve fitting model allow estimation of power loss resulting from remanent related cogging and remagnetization effects in nano-structured magnetite. Such nano-structured magnetite is shown to exhibit hysteresis losses in the order of 1 × 10−4 [W/m3] from remagnetization and 1 × 10−7[W/m3] from remanence related cogging drag. These losses are lower than those of micro-structured samples, suggesting that nano-structured materials have a significant positive effect in reducing electrical machine losses for the proposed radial multi-plattered diamagnetic bearing solution. The lower parasitic loss in these bearings suggests excellent compatibility with flywheel energy storage applications.

The thesis draws upon six published and peer reviewed papers and a peer reviewed book chapter. An overview of each paper is followed by the publication and then an explanation of how each has contributed to the emerging research profile and methodology. There follows a critical overview and rationale of the developing and emerging research profile and the move from a constructivist grounded methodology to a Bourdieuian theoretical and methodological position. This thesis focuses on the process of social reproduction and change in the contemporary mountaineering and climbing field. A central theme in this thesis is the relationship between social structure and individual agency. The adoption of the Bourdieuian approach represents a conceptual break with previous understandings of action, agency, objectivism, subjectivism, the individual and society. Habitus becomes a main mechanism to explore and analyse the process of social change and reproduction in the contemporary climbing and mountaineering field. Habitus makes it possible to understand and account for the dynamic and spontaneous actions of individuals as well as the process of social reproduction and change. At the centre of the process of social change is the relationship between the habitus and the field. It is through a detailed analysis of the relationship between the habitus and the field that is possible to understand the process of structural change and the conditions where individuals are most likely and able to challenge doxa. In the modern climbing context, women, particularly from the middle classes, are becoming empowered through the transformation of their bodies and the construction of often complex and contradictory identities. These women are placed to take advantage of new emerging social relations and opportunities occurring as a result of hysteresis. However, this has implications for the identities and position of established climbers, particularly men whose habitus was formed under a previous set of objective conditions, but also other women from subordinate social positions.

In the quest for reliable, repeatable and stable field electron emission that has commercial potential, whilst many attempts have been made, none yet has been truly distinguishable as being successful. Whilst I do not claim within this thesis to have uncovered the secret to success, fundamental issues have been addressed that concern the future directions towards achieving its full potential. An exhaustive comparison is made across the diverse range of materials that have, over the past 40-50 years, been postulated and indeed tested as field emitters. This has not previously been attempted. The materials are assessed according to the important metrics of turn on voltage, Eon, and maximum current density, Jmax, where low Eon and high Jmax are seen as desirable. The nano-carbons, carbon nanotubes (CNTs), in particular, perform well in both these metrics. No dependency was seen between the material work function and its performance as an emitter, which might have been suggested by the Fowler Nordheim equations. To address the issues underlying the definition of the local enhancement factor, β, a number of variations of surface geometry using CNTs were fabricated. The field emission of these emitters was measured using two different approaches. The first is a Scanning Electrode Field Emission Microscope, SAFEM, which maps the emission at individual locations across the surface of the emitter, and the parallel plate that is more commonly encountered in field emission measurements. Finally, an observed hysteretic behaviour in CNT field emission was explored. The field emitters were subjected to a number of tests. These included; in-situ residual gas analysis of the gas species in the emitter environment, a stability study in which the emitters were exposed to a continuing voltage loop for 50 cycles, differing applied voltage times to analyse the effects on the emitted current, and varying maximums of applied field in a search for hysteresis onset information. These studies revealed the candidate in causing the hysteresis is likely to be water vapour that adsorbs on the CNT surface. A six step model if the emission process was made that details how and when the hysteresis is caused.

In order to remain competitive in the marketplace, all motor vehicle manufacturers face difficult decisions with regard to balancing cost vs. feature. That is to say that the manufacturer must balance the cost of the product to the customer to remain competitive whilst offering appropriate technology and standard features required by that customer. All motor manufacturers are therefore under pressure to keep costs of nonfeature items to a minimum. One of the cost reductions items prevalent on most vehicles is the deletion of the structural member that attaches the rear bumper, known as the bumper beam (RBB), which is researched in this Thesis. This generates average vehicle savings of $20 and, as this is invisible to the customer, should enable the manufacturers to realise a significant saving or allow this revenue to be spent on additional feature without loss of vehicle function. However, in nearly all cases, deletion of the rear bumper beam has the effect of degrading the steering responses of the vehicle by 1 to 1½ rating points (out of 10), which is contrary to the premise of cost reductions; which is to ensure that vehicle function is unaffected. Initial analysis of vehicles with deleted rear bumper beams cannot show an objective measurable difference in any vehicle behaviours with or without the beam fitted, and hence CAE studies using ADAMS models cannot verify the effects of the bumper beam. It was necessary to employ unconventional modelling and testing methods such as rigid body, flexible body model techniques as well as experimental studies included driving robots and expert driver appraisals. The research demonstrated that vehicle modelling methods currently used, cannot establish or predict the complete vehicle ride and handling status. A total vehicle model approach should be used without separating the body CAE model and vehicle dynamics ADAMS model into separate entities. Furthermore, it was concluded that the determination to the effects of body hysteresis rather than pure stiffness is of crucial importance and that the steering attribute could be maintained with the deletion of the RBB analytically.

Disability cricket in England and Wales exists within a constant state of change. This thesis is an organizational analysis of how environmental factors foster reproduction and/or transformation within the field of disability cricket. It is important to examine how these factors are translated across multiple levels of analysis; institutional, organizational, and individual. A layered analysis is important because it attempts to overcome the limitations of previous micro- and macro-approaches to change. A reflexive ethnography that involved three years of fieldwork allowed perceptions and meanings of change to be examined in real-time. This approach is novel in studies of institutional and organizational change. Data was collected through formal and informal interviews, active-member observations, and document analysis. The findings reveal a series of structural and cognitive consequences, which included a greater number of playing opportunities for disabled cricketers and the establishment of an economic market for disability cricket which ensured organizational commitment to accepting accountability and managerial pressures. While change occurred, the nature of organizational responses to these environmental factors varied. Drawing on the theoretical insights of Bourdieu (2005) and the institutional theory of translation (Czarniawska & Sevon, 1996), I demonstrate that these responses varied between organizations because of the relationship between the field, the organization's doxa and the habitus of the individuals employed within. It concludes empirically that the translation of environmental factors is dependent on the interlinking relationships between institutions, organizations and individuals. The use of Bourdieu extends previous institutional analysis in sport management by providing a unique perspective on the role of organizations in reproducing inequality. As this thesis demonstrates institutional change is a recurrent theme in British sport organizations and further work is needed to examine the impact of these changes on the relations between sport organizations and the participants, employees and volunteers within them. As such it reinforces interdisciplinary calls to link sport management and the sociology of sport.

Innovative nanoelectronic device concepts that are beyond the scaling limits of silicon technology can have applications in future generation computations and communications, medical and security imaging, radio astronomy, etc. In particular, these devices may achieve a very high speed well beyond those of the conventional semiconductor devices. A variety of novel devices have recently been proposed including the ballistic rectifier and self-switching device (SSD). Compared with conventional rectifying diodes, both devices are based on entirely new working principles since they do not require any p-n junction or barrier structures. As a result, zero threshold voltage can be achieved, eliminating the need for a bias circuit. The planar nature of these devices means that the electrodes are placed side by side rather than on top of each other, which greatly reduces the parasitic capacitance and enables THz (1 THz = 1,000 GHz) speeds at room temperature. Despite previous work on the novel device working principles and high-speed operation, the devices have only been fabricated using conventional semiconductors. Furthermore, the research on their noise properties is so far very limited even though the device noise figures are almost as important as the speed when used as THz detectors. Manchester is the birthplace of graphene and both novel nanodevices have single-layered architecture, which is ideally-suited to use graphene as the active layer. Since the device speed generally scales with the carrier mobility, graphene based ballistic rectifiers and SSDs are expected to operate at THz frequencies. In this work, both mechanically exfoliated graphene flakes and chemical-vapour deposited graphene films have been used to fabricate the nanodevices for the first time. Their DC and radio-frequency performance have been characterised. Properties of graphene are strongly influenced by its immediate surroundings including any adsorbed molecules, interaction with the supporting substrate due to its large surface to volume ratio. Here, back-gate voltage induced hysteresis of electrical transport under normal atmospheric conditions is systematically investigated. Time-domain DC measurement and short pulse characterisation technique were employed to develop the understanding of such mechanisms, which will help to improve the stability and the reliability of graphene device properties. Finally, the noise properties of the ballistic rectifier were studied. Both thermal noise and flicker noise have been characterised. The findings have been discussed in the context of the mobility fluctuation based Hooge's empirical relation. A physical model was also constructed on the noise of a narrow constriction, and the obtained analytical expression may be applicable to a wide range of nanodevices that consist of point-contact-like structures.