This dissertation explores the limits and possibilities of science fiction at the level of television. It examines the narrative strategies of the television series Babylon 5, arguing that the programme has created a radical new sf discourse for television. In doing so, Babylon 5 has also created a new form of television narrative. The Introduction establishes the parameters of the study. Part One examines science fiction in context, considering how the genre may be identified, and in Part Two, examines its possible precursors and the influences of the epic, the Romantic novel (particularly the Gothic) and Sublime. It also considers the role and visualisation of the Western and the epic settlement of the frontier in American mytho-history. Part Three establishes the general criteria for an aesthetics of television, discussing television narrative, and examining episodic and serial drama, soap opera, before considering issues of authorship and industry. It also explores representations of sf on television with series such as Star Trek; Star Trek: The Next Generation, Deep Space Nine, Voyager, Dr Who, The X Files, Space: Above and Beyond and Stargate: SG-1. Part Four examines the five-season text of Babylon 5, arguing that in form and content it creates an ideological break with the binary ideology of the past, creating a new form of television which is both epic and novelistic, serial and episodic in nature. Part Five concludes the dissertation, proposing that Babylon 5 offers the first television epic and creates a discourse where the ideology of the past and the values of traditional television sf are questioned and subverted, resulting in a new mythos based upon the infinite discourse of diverse humanity.

Interest in the Langmuir-Blodgett (LB) technique has led to a number of investigations into different types of materials that can be deposited in the form of monolayers. For example, as well as the classic long Cham fatty acids and alcohols, materials such as polymerisable molecules, aromatic hydrocarbons and dye substances can now all be produced in monomolecular form. Unfortunately, few of these materials yet fulfil the requirements of mechanical and thermal stability that will be necessary if LB films are to be used commercially. This work has dealt with the use of phthalocyanine, a substance well known for its thermal and chemical stability, in the production of LB films. Initially two compounds were investigated, dilithlum phthalocyanine and tetra-tert-butyl phthalocyanine. Although it was found that both materials produced layers of reproducible quality which adhered tenaciously to various substrates and to each other, single monolayers were not obtained. More success has been achieved using an asymmetrically substituted phthalocyanine molecule. Electron microscopy studies have shown that the majority of films are polycrystalline. However, a substitute CuPc proved to be a valuable exception. Multilayer films of this molecule were found to have domains of the order of 3 mm in size showing a preferred orientation. Even so, it has to be accepted that the phthalocyanine films produced to date are not as structurally perfect as for example, multilayers of lo-tricosenoic acid. Our ability to produce monomolecular layers of phthalocyanine now extends the range of possible applications for this material. For instance it is known that the fine control of insulator thickness is crucial in the optimisation of photovoltaic and electroluminescent metal-lnsulator-semlconductor devices. Examples of both types of device have been demonstrated using our phthalocyaine films. For the bistable switch, a gallium arsenide substrate was used; both gallium phosphide and zinc selenlde have been utilized in the electroluminescent structures. Moreover, In the case of phthalocyanine another possibility presents Itself. It has long been known that the conductivities of this material and its derivatives are very sensitive to the presence of certain gases, particularly the oxides of nitrogen. The increased conductivity of such materials has been demonstrated to be confined to the surface of the crystal. Hence many phthalocyanine gas detector systems have been based on thin films. Unfortunately because phthalocyanine exhibits polymorphism, the exact structure of such films can be complicated. making interpretation of results and subsequent device optimisation difficult. Also the response and recovery times of these thin film devices can also be excessively long. It is possible that monomolecular LB films of phthalocyanine could well overcome some or all of these problems. Our experiments have concentrated on asymmetrically substituted copper phthalocyanine and its usefulness to detect nitrogen dioxide. Preliminary results show the response and recovery times for the simple gas structures to be faster than those previously reported for other thin film phthalocyanine devices. It is suggested that this is due to the more ordered structure of the LB film, which enables the gas to adsorb on, or desorb from the molecular sites more readily.

The behaviour of thin film semiconducting and magnetic devices depends upon the chemical and physical status of the as-grown structure. Since the dimensions of many devices can be in the Angstrom and nanometre region, characterisation techniques capable of measuring chemical and physical parameters in this regime are necessary if an understanding of the effect of specimen structure on observed properties is to be achieved. This thesis uses high resolution x-ray scattering techniques to characterise sub-micron layered structures of semiconducting and magnetic materials. Double crystal diffraction is routinely employed in the semiconductor industry for the on line inspection of sample quality. While material parameters such as sample perfection and layer composition may be rapidly deduced, the non-destructive measurement of layer thickness is more difficult (particularly for multilayered samples) and lengthy simulation procedures are often necessary to extract the thickness information from a double crystal diffraction profile. However, for semiconductor structures which act as Bragg case interferometers, oscillations (known as thickness fringes) appear in the diffracted profile. The period of these fringes can be directly related to layer thickness. Attempts to Fourier transform diffraction data, in order to automatically extract the frequency" of thickness fringes, have previously been only partially successful. It is shown that the relatively weak intensity of the thickness fringes and the presence of the substrate peak in the analysed diffraction data, drastically reduce the quality of the subsequent Fourier transform. A procedure for the manipulation of diffraction data is suggested, where an "average” envelope is fitted to the thickness fringes and used to normalise the data. The application of an auto-correlation is shown to further increase the quality of the Fourier transform of the normalised data. The application of Fourier transform techniques to the routine analysis of double crystal diffraction data is discussedA novel technique for the measurement of absolute lattice parameters of single crystals is presented, which is capable of determining lattice constants with an absolute accuracy of around 2 parts in 10(^5). The technique requires only the use of a conventional triple crystal diffractometer with motorised 20 circle movement and the provision for a fine, precise rocking motion of the analyser. To demonstrate the technique, exemplary measurements on GaAs and InAs crystals are presented. Triple crystal diffi-action analysis has been performed on three material systems of current technological interest; the Hg(_1-x)Mn(_x)Te on GaAs, the Cd(_1-x)Hg(_x)Te on CdTe/Cd(_1-x)Zn(_x)Te and the low temperature grown GaAs systems. Studies on the Hg(_1-x)Mn(_x)Te on GaAs system reveal that the principal contribution to the rocking curve widths of layers grown using the direct alloy growth (DAG) method, arise from the tilt (i.e., mosaicity) of layer sub-grains. This finding is confirmed by double crystal topography which shows that the layers are highly mosaic with a typical grain size of (130±5)µm. Topographic studies of Hg(_1-x)Mn(_x)Te on GaAs, grown using the interdiffused multilayer process (IMP), show that sample quality is significantly improved with single crystal material being produced using this growth method. Triple crystal diffraction studies of the Cd(_1-x)Hg(_x)Te on CdTe/Cd(_0.96)Zn(_0.04)Te systems reveal several findings. These are that the main contribution to rocking curve widths is from lattice tilts and that the tilt distribution increases as the layer thickness decreases. Further, the quality of the Cd(_0.96)Zn(_0.04)Te substrate analysed is superior to that of the CdTe and that Cd(_1-x)Hg(_x)Te layers grown on Cd(_0.96)Zn(_0.04)Te substrates are generally of a higher quality than those grown on CdTe. Triple crystal analysis of MBE and ALE grown GaAs films, deposited at low growth temperatures, show that, at equivalent temperatures, superior quality films are grown by the ALE technique. Narrow lattice dilation and tilt distributions are reported for GaAs films grown at temperatures as low as 300ºC by the ALE method. While diffraction techniques are highly suitable for the study of relatively perfect crystalline material, they are not appropriate to the analysis of heavily dislocated or even amorphous specimens. This is not the case for the Grazing Incidence X-Ray Reflectivity (GIXR) technique, whose sensitivity is not dependent upon sample structure. The GIXR technique is currently attracting increasing interest following the development of commercial instruments. In this thesis, GIXR has been used to probe the layer thickness and interfacial roughness of a series of magnetic multilayer samples and Si/Si(_x)Ge(_1-x) superlattices. The technique is shown to be capable of measuring layer thickness to an accuracy of one monolayer. Modelling of specular GIXR data for the Si/Si(_x)Ge(_1-x) superlattices has shown that the magnitude of interfacial roughness is different for the two types of interface within the high Ge content superlattice samples, the Si(_x)Ge(_1-x)→Si interface possessing a long range sinusoidal roughness of (0.9±0.3)nm, in addition to die short range roughness of (0.5±0.2)nm present at all interfaces. By collecting the diffuse scatter from a GIXR experiment, conformal, or correlated, roughness has been observed in both the multilayer and superlattice samples.

The application of the metalorganic chemical vapour deposition technique to the production of II-VI compound semiconductor electroluminescent devices is discussed. Both low field MIS minority carrier injection devices and high field impact excitation structures are considered, and comparisons are drawn with more commiercially orientated electroluminescent displays. The epitaxial growth of ZnS and ZnSe onto (100) orientated GaAs substrates, using the reactions between dimethyl zinc and the hydrides HgS and H2Se, is described. Details are given of a novel epitaxial MISi device processing technology, in which a ZnS I-layer also acts as an etch-stop, thus enabling chemical removal of the GaAs substrate. Metal electrodes deposited directly onto the ZnS and ZnSe allow the electrical and electroluminescent characteristics of these epitaxial II-VI compound layers to be investigated in the absence of any influence from the substrate material. X-ray diffraction and reflection high energy electron dififraction confirm that the structures are epitaxial and of excellent crystallinity. It is demonstrated in an electron beam induced current study that conduction in the epitaxial MIS devices is highly uniform, and this is manifested in a uniform spatial distribution of electroluminescence. A description is given of high field impact excitation electroluminescent devices, in which the ZnS layer is doped with manganese during MOCVD growth. The spatial distribution of EL in these devices is shown to be non-uniform, and thus indicative of filamentary conduction in the ZnS:Mn, in accordance with a recently proposed dielectric breakdown model of instability. It is demonstrated that the transient characteristics of the epitaxial structures correlate with those of commercial polycrystalline devices, and are also consistent with the predictions of a dynamic model of instability. As a result of filamentary conduction, both epitaxial and polycrystalline devices are prone to degradation through localised dielectric breakdown. These breakdown events generally result in a gradual erosion of the active electrode area, although, under certain operating conditions, mobile filaments can cause rapid destruction of epitaxial structures. The columnar microstructure of sputtered devices appears to prevent such filament mobility, and it is concluded that, although filamentary conduction is a result of the carrier injection mechanism and is independent of the crystallinity, the associated damage is strongly influenced by the microstructure of the device.

This thesis presents an experimental investigation into a compressible turbulent wall jet issuing from a slot, and flowing over a surface with streamwise curvature, followed by a plane wall recovery region. The purpose of this data was to provide suitable test cases to aid in the design and validation of turbulence models used for curved flow situations in computational fluid dynamics. The presence of streamwise curvature provides an extra rate of strain to the flow which effects both the mean flow field and the turbulence structure. The effects of curvature are dependent on the ratio of the slot width to the radius of curvature. The effects are increased with the magnitude of this ratio. Hot film anemometry was used to measure the mean flow and Reynolds stresses under six different flow regimes. Four experiments were performed using a constant slot to radius ratio, and the supply pressure ratio was varied. Two further experiments were performed at a constant pressure ratio, but at differing slot to radius ratios. In all cases, the extra rate of strain was found to increase the jet growth and velocity decay rates beyond those of a plane wall jet. 'History effects' were apparent where there was a change from flow with streamwise wall curvature to that without. The turbulence structure was found to require a finite distance along the recovery section before it reverts to a plane wall turbulence structure. The presence of the extra rate of strain, and the history effects at sudden changes in surface curvature, make strong demands on any turbulence model. Various turbulence models have been tested, and although no one turbulence model has proved robust enough for all flow situations, a number of models have been identified to provide superior performance under certain conditions. The use of a higher order numerical scheme has also been found to reduce the effects of numerical diffusion, leading to improvements in the predictions of the flow shock cell structure and the breakaway performance of the jet.

The fabrication of pyroelectric devices using the Langmuir-Blodgett (LB) technique is described. Studies of a wide range of materials are reported; however, the thesis concentrates on electrical and structural investigations of two specific alternate layer films: 22-tricosenoic acid/l-docosylamine and 22-tricosenoic acid/4-octadecylaniline. The latter system possesses a pyroelectric coefficient of 0.65 nCcm(^-2)K(^-1), representing the largest reported value, to date, for an LB film. The pyroelectric figure of merit (p/e(^1)(_T)) of such films is approximately 0.22 nCcm(^-2)K(^-1), which is comparable with the values for commercially available materials. The difference in pyroelectric coefficient of the two types of alternate layer film is attributed to differences in inter-layer bonding, as revealed by infrared spectroscopy. The dependence of the pyroelectric coefficients on parameters such as film thickness, substrate thickness and temperature is investigated. Structural studies, performed using electron and X-ray diffraction techniques, are also described. These provide information on the orientation of the molecules relative to the substrate and on the d-spacing of the LB films. It is shown that the substrate has a deleterious effect on the responsivity of LB film devices, and studies of films deposited onto different substrate materials indicate that there is a significant piezoelectric ally induced secondary effect contributing to the overall pyroelectric coefficient. This secondary effect is small at low temperatures, but becomes dominant at around 250 K. The results of thermally stimulated discharge experiments indicate that both free charges and dipolar groups are incorporated in the films during deposition, and become tightly bound within the polar structure.

No description available.

No description available.

The animated films of Walt Disney have played an important role in American culture. Most Americans, either during childhood or adulthood, have been exposed to at least some of them. The films themselves have, in some respects, reflected American society and culture. They may also, at least to some extent, have influenced them. As academic scholarship on the history of Hollywood film has grown, various aspects of Disney's influence and cultural position have likewise come to be the focus of study. In recent decades, also, there has been a continually greater interest in the role of women in American society and how that role is constructed. Uniting both these scholarly interests, this thesis analyses how Disney films depict femininity, and the ways in which such depictions correspond with those in the larger arena of Hollywood film. To make these issues more comprehensible, it describes the beginnings of animated film in the United States, together with the early career and works of Walt Disney. In order to cast light on the manner in which such portrayals have changed over time, the films examined are analysed in relation to three particular time periods: 193 7-67, 1967-89, and 1989-99. By examining the depictions to be found within individual films, and comparing these depictions both with one another and with selected live-action, mainstream Hollywood films of the same eras, a better understanding of the make-up of the Disney films as a body of work is achieved, and a corrective offered to some of the misconceptions of Disney to be found within American society in general.

Auteurist approaches developed in the 1950s studied films as a means of personal expression, valuing those directors who could bring an individual quality to their films as 'auteurs' . More recent theories of subjectivity and textuality have displaced the centrality of the director as author of meanings in the film texts, but have had difficulty in explaining the continued importance accorded to directors in interviews and writing about their films. The interaction of directorial intention, film industry, and the use of other media to communicate the director's ideas to audiences is an area of continued theoretical concern. It is the aim of this work firstly to examine how Francesco Rosi has managed to constitute himself as an 'auteur' within the institutional structures of the Italian film industry, and the constraints which these impose. Between 1958 and today Rosi has made fifteen films, the majority of which to a greater or lesser extent engage with the reality of contemporary Italy. He works within the mainstream of the Italian film industry. His work can, however, be located within that narrow band of 1- 2% of films produced each season which can be designated 'art' or 'quality' cinema, as opposed to more or less formulaic genre products. This study aims to show that the institutional structures of the Italian film - and latterly media - industries have a primary influence both on the particular narrative patterns Rosi has at his disposal, and on the particular types of films which Rosi as director is financed to make. Secondly, I examine elements of Rosi's films which mark him out as an 'auteur'. Through close textual analysis, I identify recurring visual, rhetorical and narrative choices which can be shown to signal the presence of the 'auteur', Rosi, in the film texts, and to constitute his style.