A special application of optical wireless data transfer, namely on-line monitoring and diagnostic of rotors in turbines and engines, has been considered in this thesis. In this application, to maintain line of sight, i.e. data transfer, between a sensor placed on a rotating comp…
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Organic photovoltaics (OPVs) is an area that has attracted much attention recently as a potential low cost, sustainable source of energy with a good potential for full-scale commercialisation. Understanding the factors that determine the efficiency of such cells is therefore a h…
Promising techniques such as micro-stereolithography (MSL) are opening up practical potential for exploiting new ideas for specialized polymer-based Micro-Electromechanical systems (MEMS) through small-batch production. As the field matures and grows, substantial research and co…
Despite the profound implication of blogs for marketing communications, there are very few theoretical and empirical studies on this emerging social phenomenon. This study is one of the first to investigate how blog users engage with blogs. Specifically it looks at the relations…
One of the main trend in the development of high power electric machines (motors, generators) is to replace the magnetic components with superconducting wires, this inevitably leads to a critical requirement from the industry (Converteam) to operate power devices at cryogenic te…
This thesis contributes the research and development of novel receiver optimization approaches conducted in ultra-wide bandwidth (UWB) systems. The ultimate goal of the improved receiver technology is to simplify the receiver structures at the cost of a tolerable performance deg…
Wireless communications are experiencing an unprecedented expansion. The increasing mobility of the communication society and the pace of technological change are growing pressure for more spectrum to support more users, more uses and more capacity. Thus, spectrum management has…
Mathematical and computer-based models provide the foundation of most methods of engineering design. They are recognised as being especially important in the development of integrated dynamic systems, such as “control-configured” aircraft or in complex robotics applications. The…
This thesis presents the development and test of an integrated ion camera chip for monitoring highly localised ion fluxes of electrochemical processes using an ion sensitive sensor array. Ionic concentration fluctuations are shown to travel across the sensor array as a result of…
This thesis is concerned with the design, fabrication and characterisation of high power semiconductor mode locked lasers (SMLLs), operating at ~ 1.5 μm. The devices are based on a novel epitaxial structure with three quantum wells (QW) in the active region. The novel epitaxial …
This thesis describes the reliable design of tunnel diode and resonant tunneling diode (RTD) oscillator circuits. The challenges of designing with tunnel diodes and RTDs are explained and new design approaches discussed. The challenges include eliminating DC instability, which o…
The growing variability of electrical characteristics is a major issue associated with continuous downscaling of contemporary bulk MOSFETs. In addition, the operating conditions brought about by these same scaling trends have pushed MOSFET degradation mechanisms such as Bias Tem…
Abstract It has been reported that as much as 12% of global electricity production goes into producing artificial light using arc discharge lamps and that global annual production of these lamps may be as much as 1.2 billion units. In the liquid steel production industry, one me…
In this work, the need for an integrated optical dispersive device is discussed, with particular reference to pulse compression of semiconductor mode-locked laser (MLL) pulses that exhibit temporal chirp and therefore, worse than transform limited behaviour. It is shown that cur…
Epoxy resin is widely used in high voltage apparatus as insulation due to its excellent mechanical, electrical and chemical properties. Fillers are often added to epoxy resin to enhance its mechanical, thermal and chemical properties. With the new development in nanotechnology, …
Electrical insulation is known to age when under electrical stress. One cause of this is thought to relate to the movement and build up of charge within the insulation. The emission of a low level of light from polymeric materials when under electrical stressing is shown to occu…
Visual surveillance finds increasing deployment for monitoring urban environments. Operators need to be able to determine identity from surveillance images and often use face recognition for this purpose. Unfortunately, the quality of the recorded imagery can be insufficient for…
Detecting and dealing with congestion in delay tolerant networks is an important and challenging problem. Current DTN forwarding algorithms typically direct traffic towards particular nodes in order to maximise delivery ratios and minimise delays, but as traffic demands increase…
A Quadrupole Mass Spectrometer (QMS) is an instrument for measuring concentrations of atoms and molecules by separating atomic and molecular ions according to their mass-to-charge ratios (m/z). It consists primarily of an ion source, quadrupole mass filter (QMF) and detector. Ge…