7 resultados para Soluble Form

em WestminsterResearch - UK


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There has been much discussion since the mid-1980s about the relationship between transport and urban form. However, all of this body of research has concerned itself with passenger transport (i.e. the movement of people). This report is intended as an initial investigation into the relationship between road freight transport and urban form. Important trends in road freight transport and logistics and the land use associated with these activities are discussed. Data about road freight transport activity by heavy goods vehicles (HGVs) in Britain that has been disaggregated from a UK government survey is analysed to investigate the nature of urban freight operations in sixteen selected urban areas. This includes analysis of the efficiency and transport intensity of these operations on journeys to, from and within each urban area. Scenarios concerning urban freight operations based on reductions in length of haul, and improvements in vehicle lading factors, vehicle carrying capacities and empty running are constructed in order to investigate the potential effect of such changes on the vehicle kilometres performed on journeys to, from and within the sixteen urban areas.

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This paper examines road freight transport activity and its relationship with facility location, logistics management and urban form through an analysis of 14 selected urban areas in the UK. Improved understanding of this relationship will assist planners when making transport and land use decisions. The findings suggest that several geographical, spatial and land use factors have important influences on freight activity in urban areas. Commercial and industrial land use patterns affect the types and quantities of goods produced, consumed, and hence the total quantity of freight transport handled. This also influences the distances over which goods are moved and by what specific mode. There has been relatively low growth in warehousing in many of the selected areas over the last decade compared to the national average as well suburbanisation of warehousing in some locations. This affects the origin and destination of journeys visiting these facilities and typically increases the distance of such journeys. A greater proportion of road freight has been shown to be lifted on internal journeys in large urban areas than in smaller ones. Journeys within urban areas have been shown to be less efficient than journeys to and from the urban area in the 14 locations studied due to the much smaller average vehicle carrying capacities and lower lading factors for journeys within urban areas. The length of haul on journeys to and from urban areas studied was found to be greatest for those areas with a major seaport and/or which were geographically remote. This affects the road freight transport intensity of goods transport journeys.

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The aims of this work are twofold. On the one hand, it aims to find evidence supporting the presence of the weak form efficiency of several emerging African stock markets by using both parametric as well as non parametric tests. The results indicate that none of the markets are characterised by random walks with the exception of the South African stock market. On the other hand, this study aims to detect the presence of the day of the week effects of these African stock markets. Results show the existence of day of the week effects, that is the typical negative Monday and Friday positive effects in several stock markets.

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This article discusses a curatorial approach to authorship as a model for thinking about what I describe as an iterative modular poem, a poetic text composed of appropriated segments. As a response to contemporary proliferation of literary and artistic works created by iterative means, i.e. through acts of appropriation, remixing and remediation, the article is an attempt at putting forward ‘the curatorial’ as an emerging paradigm of writing for the twenty-first century. The article approaches established paradigms of authorship, creativity and originality as inadequate with respect to contemporary experimental poetic practices to suggest a shift from creating to collecting and curating as a possible alternative model for thinking about instances of iterative creative writing. The argument focuses on Robert Fitterman’s Holocaust Museum (2011) as an example of an iterative modular poem and a text emblematic of such curatorial approach to authorship.

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A modified tri-axial electrospinning process was developed for the generation of a new type of pH-sensitive polymer/lipid nanocomposite. The systems produced are able to promote both dissolution and permeation of a model poorly water-soluble drug. First, we show that it is possible to run a tri-axial process with only one of the three fluids being electrospinnable. Using an electrospinnable middle fluid of Eudragit S100 (ES100) with pure ethanol as the outer solvent and an unspinnable lecithin-diclofenac sodium (PL–DS) core solution, nanofibers with linear morphology and clear core/shell structures can be fabricated continuously and smoothly. X-ray diffraction proved that these nanofibers are structural nanocomposites with the drug present in an amorphous state. In vitro dissolution tests demonstrated that the formulations could preclude release in acidic conditions, and that the drug was released from the fibers in two successive steps at neutral pH. The first step is the dissolution of the shell ES100 and the conversion of the core PL–DS into sub-micron sized particles. This frees some DS into solution, and later the remaining DS is gradually released from the PL–DS particles through diffusion. Ex vivo permeation results showed that the composite nanofibers give a more than twofold uplift in the amount of DS passing through the colonic membrane as compared to pure DS; 74% of the transmitted drug was in the form of PL–DS particles. The new tri-axial electrospinning process developed in this work provides a platform to fabricate structural nanomaterials, and the core–shell polymer-PL nanocomposites we have produced have significant potential applications for oral colon-targeted drug delivery.