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This thesis is concerned with ensuring high energy resolution from the swept charge device (SCD) CCD54, essentially a non-pixellated version of the charge coupled device (CCD), for use in the Chandrayaan-1 X-ray Spectrometer (C1XS). Of particular interest is the effect on performance due to the radiation damage, caused by protons, the CCD54s used in C1XS will receive during the transfer to the Moon and during the two years in lunar orbit. Chapter 2 reviews the atomic structure, the formation and detection of X-rays, and the operation of a CCD. Chapter 3 discusses the space radiation environment and the damaging effects it has on CCDs, for example increasing dark current and charge transfer inefficiency. Chapter 4 presents the basic laboratory equipment and procedure used during the experimental work, and details the initial optimisation and characterisation, the pre-flight characterisation of devices available for use in C1XS, the measurement of the depletion depth, and quantum efficiency of the CCD54. Chapter 5 details the results of the initial proton irradiation study, intended to demonstrate the ability of the CCD54 to provide excellent scientific data over the two years at the Moon. Chapter 6 describes a second irradiation study covering a more detailed investigation of the damage effects, investigating dark current, trap energy levels, and charge transfer inefficiency. Chapter 7 describes work conducted to assist the C1XS science team in the development of an X-ray fluorescence model, to be used with X-ray spectra provided by the X-ray solar monitor and the spectra detected by C1XS, to provide elemental abundance information of the lunar surface. It also presents the initial C1XS results from the Moon, and a brief comparison of the CCD54 with other semiconductor X-ray fluorescence detectors. Chapter 8 describes the final conclusions and recommendations for further work, including a study of the radiation damage effects during the two years at the Moon and the future development of SCD detectors for use in space.

The Albury and Powerscourt prophetical conferences saw the birth of a new form of premillennial dispensationalism that has shaped evangelical eschatology ever since. It owed its debut to John Nelson Darby, who espoused the centrality of the "two peoples of God." Dispensationalism affirmed three cardinal doctrines: first, a sharp dichotomy between the two peoples of God-national Israel and the church; second, God's glory rather than the covenant of grace defining His purpose in history; and third, the hermeneutical principle of a literal interpretation of Scripture. This dispensationalism was indeed revolutionary, displacing the traditional historicist hermeneutic, with its system of date-setting, in favour of futurism, with its doctrine of imminency. This forced Darby to deal with the problem of what to do with the church so that God could fulfil his redemptive plan regarding national Israel. He resolved this by providing for a rapture of the church and by inserting a gap of an indeterminate number of years in the last part of Daniel's seventy-week prophecy. The question that arises over this new doctrine of premillennial, pretribulational dispensationalism concerns its provenance, since Darby is widely credited as its originator. There is good reason for this. His influence can be seen in C. I. Scofield's Reference Bible, as well as such popular novels as Hal Lindsey's The Late, Great Planet Earth and Timothy LaHaye's Left Behind series. There are two dominant schools of thought regarding Darby and the origin of dispensationalism. One traces his dispensationalism back to the Patristic Writings, and the other sees Darby as "inventing" his system. Both are incorrect, as I will demonstrate by tracing his eschatology to earlier thinkers to show that Darby "adapted" extant doctrines to form his unique system. This dissertation will establish a much more coherent picture of Darby and his contribution to the field of eschatology by identifying the sources that were available and were adapted by him to form his premillennial dispensationalism. This will also provide a greater understanding of the modern "revisionist" and "progressive" forms of dispensationalism.

This qualitative research is an exploration of the experiences of student teachers during teaching practice as a component of initial teacher education in Malawi. The research was necessitated by a general lack of knowledge about secondary school teacher education in Malawi and the view that teaching practice is one of the major components of concern for professional learning among student teachers. An activity theory perspective provided a theoretical and conceptual lens of understanding teaching practice. The elements within activity theory which were of particular significance related to tools/artefacts, subjects, objects and outcomes in teaching practice; rules/norms within an activity system of teaching practice; perceptions of individuals about teacher education and a teaching activity; pedagogical actions and understanding during teaching practice; the community relationships in school systems where student teachers carried out teaching practice; division of tasks; activity settings; tensions/contradictions, as well as innovations within the activity of teaching practice (Engestrom, 1999). The participants in the study were drawn mainly from student teachers on a three-year teacher education programme at one of the teacher education institutions in Malawi. The results from the study showed that the student teachers had different perceptions for teaching as well as differing goals for joining a secondary school teacher education programme; that student teachers had varied experiences during teaching practice and the varied experiences influenced learning to teach in various ways. The shortage of material resources impeded some activities that student teachers could carry out. The findings showed that some pedagogical tools that student teachers had learned in college were not always easily used in the schools. The community relationships between student teachers and teachers in the schools affected professional development in some way. The supervision component of teaching practice also generated mixed experiences from student teachers. The study participants proposed innovations aimed at resolving some of the tensions and contradictions faced during teaching practice. The innovations related to facilitative supervision, holistic assessment, changing the time and duration of teaching practice as well as student teachers' placements. The enriched understanding of the experiences of the student teachers makes significant contribution to knowledge within teacher education in Malawi.

Optical communication was developed to allow high-speed and long-distance data transmission and is currently a £6bn market. This has also led to the adoption of optical technologies in other areas including the CD, DVD and medical imaging systems. Standardisation of components means that these systems require light sources that operate near the 1310 and 1550 nm telecommunications windows but existing lasers here are expensive due to their high temperature sensitivity. The exploitation of quantum con¯nement has led to the development of \quan- tum dot" (QD) laser material because of predictions of huge gains in performance. Emission wavelengths of InAs/GaAs QD lasers have been extended to the telecom- munications window near 1300 nm by various growth technologies and the first commercial devices have recently been brought to the market. However, progress to longer wavelengths has been stalled for several years as well as the speed and tem- perature sensitivity of these devices falling short of the predictions; partly because QDs are grown by self-assembly resulting in a random distribution of sizes, compo- sitions and strain-states, leading to inhomogeneous broadening which is a departure from the ideal \atom-like" system. This work details the growth, design and development of QD bilayer laser devices, which o®er a unique approach to fixing these shortcomings. When two QD layers are grown close together; the first layer provides a template that allows larger, more uniform QDs to be grown in the second layer, giving greater uniformity and deeper confinement. This has the potential to increase the efficiency and to achieve emission wavelengths out towards the more-commonly used telecommunications window at 1550 nm directly on GaAs substrates. Multiple bilayer laser diodes with inhomge- neous broadening of less than 30meV, lasing at up to 1430 nm and room-temperature photoluminescence at 1515 nm are shown. Despite the vastly reduced inhomogeneous broadening of QD bilayers, it is still found to be a relevant factor due to the change from de-localised geometries of quantum wells to an ensemble of separate QDs. It will be shown that understanding this is essential for describing the observed optical and electrical behaviour of the laser diodes.

This thesis addresses the governance of Nottinghamshire during the first thirty three years of the reign of Edward III. The time-frame is significant as it seeks to re-dress an imbalance in the study of provincial societies during the later Middle Ages, which hitherto have largely concentrated on the second half of the fourteenth and fifteenth centuries. The most important belief to be addressed is that those who were engaged in the governance of Nottinghamshire were drawn from a considerably wider section of society than is apparent from previous county or regional gentry-based studies. It will also demonstrate the close nature of the relationship between the shire and the crown, which manifested itself in a wide variety of channels of communication. Chapters one and two look at the formal structures of government in Nottinghamshire. The focus for these chapters will be upon the whole of the county, as this reflects the crown's approach to governance. Chapter one will address the offices of local government, and chapter two will look at the pivotal relationship between the locality and the crown, concentrating upon parliamentary representatives and petitions. These chapters will also assess the impact of war and the Black Death upon Nottinghamshire. For subsequent chapters, the geographical focus of the study will be reduced to that of south Nottinghamshire, which will facilitate a more in-depth analysis of law and order in chapter three, and landholding in chapter four. The study will then -conclude with a case-study upon a smaller area within south Nottinghamshire. Throughout, this thesis will address significant historiographical debates. The most important of which relates to the impact upon provincial societies and local government of bastard feudalism, and to the related debates over the vertical and horizontal ties of lordship, and to the existence or otherwise of an 'independent gentry', and of 'county communities'.

The application of supercritical C0₂(scC0₂) as a solvent for the synthesis of fine and bulk chemicals has been well documented; however its application as a solvent for the synthesis of pharmaceuticals is yet to be exploited fully. To address this issue, two synthetically important reactions have been investigated in scC0₂; chemoselective N-debenzylation and diastereoselective hydrogenation. Chapter 3 details the study of catalytic N-debenzylation in the presence of sensitive functional groups (COMe and Cl). It has been shown that selective N-debenzylation in the presence of a carbonyl (COMe) is difficult to achieve due to the high operating temperatures that are required to facilitate continuous flow debenzylation. N-debenzylation in the presence of chloro- substituents was also investigated. Dechlorination can be a major problem during this reaction however several different strategies were developed to suppress dechlorination including: (i) the correct selection of catalyst support; (ii) selective poisoning of a Pd catalyst; (iii) the addition of acids, such as H₂S0₄ to the reactant stream; (iv) the use of an aprotic co-solvent, such as THF. Chapter 4 covers progress made on the diastereoselective hydrogenation of the pharmaceutical intermediate, rac-sertraline imine. It has been shown that the hydrogenation reaction can be performed with excellent levels of chemo- and diastereoselectivity (cis:trans ratio of 97:3, 0.7 % by-product formation) by performing the reaction as a continuous flow process in the presence of scC0₂ All details of the apparatus, experimental and synthetic procedures are reported in Chapter 2.

The use of an A1N interlayer to allow the growth of crack-free AlGaN on a GaN template is investigated. The impact of using an A1N interlayer on the active region of a device is examined by investigating a series of GaN/AlGaN quantum well structures. It is observed by WBDF that the a-type dislocations generated at the A1N interlayer form ‘staircase’ structures in the quantum well stack where all dislocation segments are in edge orientation A model is proposed where misfit dislocation segments at each well interface are formed by climb, in contrast to the dislocation glide at the lowest interface that might be expected in other systems. Both HAADF imaging and conventional TEM are used to characterise a series of Al-GaN/GaN quantum cascade laser (QCL) structures. These devices have great potential in the field of fibre optic communication. Changes in the layer spacing near V-defects, and the effects that changing substrate from sapphire to bulk GaN have on the mechanisms for relaxation in this system are identified and discussed.

This dissertation marshals a range of new evidence to reconstruct the 12th to 13th century Buddhism and sacred art of king Jayavarman VII. It traces political and cultural roots reaching back to the rise of Tantric Buddhism in eighth century Pala India. It links developments in peninsular pre-Thailand and across the Korat plateau with 10 th century temple art and inscriptions in Cambodia, where a Buddhist revival was influenced by the yogatantras, the first Tantras opening the 'path of vajra' or Vajrayana. The evidence for Tantric Khmer Buddhism is gleaned from a new translation of a key Sanskrit inscription and from sacred relief carvings. An analysis of the 11-12th century sacred art of Phimai, a major foundation in modern Northeast Thailand, evinces the arrival of the mature Vajrayanist yoginTtantras sustaining a Buddhist dynasty, which had seized power in Angkor and would later invest its religious beliefs in the Bayon. The phased building plan of Jayavarman VII's many temples and the iconography of the Bayon-style are reassessed, bringing to bear previously unpublished data from the king's large temple of Banteay Chmar northwest of Angkor. The reign of Jayavarman VII is substantially reconfigured, presenting his methodical introduction of new doctrine and consequent political dominance via carefully orchestrated stages which subjected the entrenched Brahmanical elite to politico-religious campaigns of consecrations to Lokesvara and ultimately to Hevajra and Vajrasattva. Throughout this thesis, exhaustive analysis is made of existing scholarship, which is confronted with a substantial body of new epigraphic and iconographic data.

The empirical focus of this thesis is the history of history teaching between 1880 and 1914. In particular, it constitutes a study of the intentions which underpinned wrical education. Much of the scholarly research on history teaching's past uses on the history lesson as a site for the downwards filtration of imperia, ideologies into the nation's consciousness, the source material for which has mainly been the subject-specific history textbook. The textbook, however, does not properly reflect the genre of text which the majority of children would have read in their lessons in history. This thesis shifts the focus and thus offers a contribution to knowledge by examining sources which, although largely absent in previous studies, play a significant role in helping us better understand the perceived values of historical education. This thesis, therefore, connects the recommended practice of the historical reading lesson and contemporary educational theory. It is the first substantial study to do so.

The osmium-mediated aminohydroxylation reaction is a powerful oxidation that introduces a hydroxyl group and a protected amino group in a syn relationship across an olefinic double bond. This study concerns one approach to controlling the regioselectivity of this oxidation. Introduction I The mechanism, scope and limitations of the aminohydroxylation reaction are discussed, with particular attention to the asymmetric version, providing a background from which the newly developed methodology has emerged. Results and Discussion I Development of the reaction This section concerns the original attempts to perform the tethered aminohydroxylation reaction, and early process optimisation to maximise the yield of aminohydroxylated product produced. Scope of the reaction This section details the results of the TA reaction as applied to further allylic carbamates demonstrating the applicability of the reaction to other olefinic geometries. The diastereoselectivity of the reaction in cyclic and acyclic systems is reported, and a model to explain the observed results discussed. Also covered within are the syntheses of the various substrates and proof of the stereochemistry of the products. Mechanistic investigations Work involving attempts to isolate a catalytic intermediate from the reaction is described. A crystal structure of this intermediate is discussed. Introduction II The isolation and physiological properties of the antibiotic compound hygromycin A are described. Prior synthetic routes towards this compound are discussed. Results and Discussion II Three approaches towards the aminocyclitol unit of hygromycin A, employing the tethered aminohydroxylation reaction, are outlined. Two of these allow for potential future development and completion of the synthesis.

When partially closed, steam turbine governing valves rely on flow separation from the valve head and seat to generate loss and throttle the flow. The aim of this type of valve is to avoid separation and therefore eliminate loss when the valve is fully open, and to have stable and controllable separations at all other valve lifts. Any significant unsteadiness in the valve flow can result in unacceptable mechanical vibration of the valve, which in extreme cases can lead to failure. Results will be discussed from work that has been undertaken into valve flow instabilities at Leicester University Engineering Department in collaboration with Alstom Energy Ltd. At high lifts, the Mach number of the steam flow between the head and the seat is sufficiently low for the fluid to be considered as incompressible. Water was therefore used as the working fluid in the tests at Leicester to model accurately the flow in a fifth scale acrylic model valve under high lift conditions. Results from laser light sheet visualisation, Particle Image Velocimetry and transient pressure measurements of the valve flow are presented. Laser light sheet illumination and high-speed Cine photography have been used to visualise the highly three dimensional valve flow. A range of valve head geometries has been tested. The results of the flow visualisation show the presence of stable and unstable separation zones and their influence on the valve flow. Particle Image Velocimetry has provided quantitative information on these features. Methods for stabilising the separation zones by modifying the valve head and seat have also been investigated and the results from these tests have shown improvements in reducing valve exit pipe unsteadiness.