7 resultados para Structure ordering

em Deakin Research Online - Australia


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The emergence of Indochina in the French imagination was articulated in both representational and institutional modes. Representation involves the transmission of colonial ideals through more obtuse means; that is, through literary texts, travelogues, exhibitions, film and advertising. However, these textual sites feed from and invest in a material situation, which was the institutional arm of colonialism. Indochina was institutionally articulated in cartographic maps and surveys, in the new social spaces of cities and towns, in architectural and technological forms, through social technologies of discipline and welfare and in cultural and religious organisations. The aim of this thesis is to analyse, across a number of textual sites, the representation and institutionalisation of Otherness through the politics of space in the French colony of Indochina, Indochine in this sense becomes a spatial discourse. The French constructed a mental and physical space for Indochina by blanketing and suffocating the original cultural landscape, which in fact had to be ignored for this process to occur. What actually became manifest as a result of this projection stemmed from the French imagination. Just as the French manipulated space, language also underwent the same process of reduction. The Vietnamese script was latinised to make it more 'useable' and ‘accessible’. Through christening the union of Indochina; initiating a comprehensive writing reform; and renaming the streets in the colonial cities, the French used language us another tool for 'making transparent'. Furthermore, the colonial powers established a communication and transport network throughout the colony in an attempt to materialise their fictive (artificial) vision of a unified French Indochinese space. The accessibility and design of these different modes of transport reflected the gendered, racial and class divisions inherent in the colonial establishment. At the heart of representing and institutionalising Indochina was the desire to control and contain. This characterised French imperial ordering of space in the city and the rural areas. In rural areas land was divided into small parcels and alienated to individuals or worked into precise grids for the rubber plantation. In urban centres the native quarter was clearly demarcated from the European quarter which functioned as its modern, progressive Other. The rationale behind this segregation was premised on European, nineteenth century discourses of race, class, gender and hygiene. Influenced by Darwinian and neo-Lamarkian theories of race, this biological discourse identified the 'working class', 'women' and 'the native' as not only biologically but also culturally inferior. They were perceived as a potential, degenerative threat to the biological, cultural and industrial development of the nation. In the colonial context, space was thus ordered and domesticated to control the native population. Coextensively, the literature which springs from such a structure will be tainted by the same ideas, and thus the spaces it formulates within the readers mind feed on and reinforce this foundation. Examples of gender and indigenous narratives which contest this imaginative, transparent topography are analysed throughout this thesis. They provide instances of struggle and resistance which undermine the ideal/stereotypical level of architectural and planned space and delineate an alternative insight into colonial spatial and social relations. The fictional accounts of European women and indigenous writers both challenge and reaffirm the fixity of some of these idealised colonial boundaries. In various literary, historical, political, architectural and cinematic discourses Indochina has been und continues to be depicted as a modern city and exotic Utopia. Informed by the mood of nostalgia, exotic images of Indochina have resurfaced in contemporary French culture. France's continued desire to create, control and maintain an Indochinese space in the French public imagination reinforces the multi-layered, interconnected and persistent nature of colonial discourse.

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X-ray diffraction (XRD) was employed to characterize electrochemically synthesized polypyrrole (PPy) films with 1,5-naphthalene disulfonate (1,5-NDS) counterions treated with simple acid and base. Results show that the as-synthesized film is amorphous with short-range ordering in the polymer backbone. This ordering is soon lost after thermal ageing at 150°C for 60 days and there is evidence of counterion degradation. Base treatment of the PPy/1,5-NDS films has similar effects leading to a complete loss of ordering in the polymer backbone and dedoping of the polymer. Acid treatment at high temperatures increases the ordering of the polymer backbone and results in the development of a secondary interdopant peak confirming that ion exchange has occurred. Conductivity of the PPy was also increased substantially. The enhanced ordering was maintained even after thermal ageing. Room-temperature acid treatment also results in improved ordering of the polymer as well as the counterion but the increase in conductivity is only marginal and most of the ordering is soon lost after thermal ageing. Increase in ordering of the polymer structure seems to lead to better conductivity, although not necessarily improved thermal stability.

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Measurements of the force as a function of distance between two solids separated by a liquid crystal film give information on the structure of the film. We report such measurements for two molecularly smooth surfaces of mica separated by the nematic liquid crystal 4'-n-pentyl 4-cyanobiphenyl (5CB) in both the planar and homeotropic orientations at room temperature. The force is determined by measuring the deflection of a spring supporting one of the mica pieces, while an optical technique is used to measure the film thickness to an accuracy of ± (0.1-0.2) nm. The technique also allows the refractive indices of the nematic to be measured, and hence a determination of the average density and order parameter of the liquid crystal film as a function of its thickness. Three distinct forces were measured, each reflecting a type of ordering of the liquid crystal near the mica surfaces. The first one results from elastic déformation in the liquid crystal ; it was only observed in a twisted planar sample where the 5CB molecules are oriented in different directions at the two mica surfaces. The second, measured in both the planar and homeotropic orientations, is attributed to an enhanced order parameter near the surfaces. Both of these are monotonic repulsive forces measurable below 80 nm. Finally, there is a short-range force which oscillates as a function of thickness, up to about six molecular layers, between attraction and repulsion. This results from ordering of the molecules in layers adjacent to the smooth solid surface. It is observed in both the planar and homeotropic orientations, and also in isotropic liquids.

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V2O5·nH2O nanosheets are fabricated hydrothermally with the acidified peroxovanadate solution at 200 °C for 12 h. The X-ray diffraction suggests that V2O5·nH2O nanosheets display lamellar ordering along c-axis direction. Transmission electron microscopy, field-emission scanning electron microscopy, and selected area electron diffraction indicate that V2O5·nH2O nanosheets are very thin in thickness and micron-sized in lateral dimension, and they are two-dimensional crystallites. X-ray photoelectron spectroscopy and thermogravimetric analysis are utilized to confirm the elemental composition of nanosheets. The formation process of nanosheets is also discussed in terms of time- and temperature-controlled experiments.

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We study an Fe-18Al (at.%) alloy after various thermal treatments at different times (24-336 h) and temperatures (250-1100 °C) to determine the nature of the so-called 'komplex' phase state (or "K-state"), which is common to other alloy systems having compositions at the boundaries of known order-disorder transitions and is characterised by heterogeneous short-range-ordering (SRO). This has been done by direct observation using atom probe tomography (APT), which reveals that nano-sized, ordered regions/particles do not exist. Also, by employing shell-based analysis of the three-dimensional atomic positions, we have determined chemically sensitive, generalised multicomponent short-range order (GM-SRO) parameters, which are compared with published pairwise SRO parameters derived from bulk, volume-averaged measurement techniques (e.g. X-ray and neutron scattering, Mössbauer spectroscopy) and combined ab-initio and Monte Carlo simulations. This analysis procedure has general relevance for other alloy systems where quantitative chemical-structure evaluation of local atomic environments is required to understand ordering and partial ordering phenomena that affect physical and mechanical properties.

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Short-range-order (SRO) has been quantitatively evaluated in an Fe-18Al (at%) alloy using atom probe tomography (APT) data and by calculation of the generalised multicomponent short-range order (GM-SRO) parameters, which have been determined by shell-based analysis of the three-dimensional atomic positions. The accuracy of this method with respect to limited detector efficiency and spatial resolution is tested against simulated D03 ordered data. Whilst there is minimal adverse effect from limited atom probe instrument detector efficiency, the combination of this with imperfect spatial resolution has the effect of making the data appear more randomised. The value of lattice rectification of the experimental APT data prior to GM-SRO analysis is demonstrated through improved information sensitivity.

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This study examines intermolecular interactions of a monolayer of octadecanol (CH(3)(CH(2))(17)OH) on water as a function of surface density and temperature, using classical molecular dynamics simulations. We observe increased interaction between the alkyl chains (van der Waals) and hydroxyl groups (H-bonding) with increased surface density, which leads to increased order and packing within the monolayer. We also identified clear trends in the intermolecular interactions, ordering and packing of the monolayer molecules as a function of temperature. The observed trends can be closely related to features of the current empirical theories of evaporation resistance.