2,523 research outputs found

    Group analysis of a class of nonlinear Kolmogorov equations

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    A class of (1+2)-dimensional diffusion-convection equations (nonlinear Kolmogorov equations) with time-dependent coefficients is studied with Lie symmetry point of view. The complete group classification is achieved using a gauging of arbitrary elements (i.e. via reducing the number of variable coefficients) with the application of equivalence transformations. Two possible gaugings are discussed in detail in order to show how equivalence groups serve in making the optimal choice.Comment: 12 pages, 4 table

    Quantifying the Variation in Protein Content in White Clover (\u3cem\u3eTrifolium Repens\u3c/em\u3e L.)

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    White clover (Trifolium repens L.) is the main legume in temperate pastures. It has relatively low levels of water-soluble carbohydrate but produces forage of high quality with a high crude protein (CP) content and dry-matter digestibility (Beever, 1993). Some studies have suggested that the forage quality of white clover can be problematic because its high CP content may contribute to inefficient use of nitrogen in the rumen and exacerbate diffuse pollution via excreta (Waghorn & Caradus, 1994). The development of white clover germplasm with lower CP content would potentially benefit forage production and grassland management. A study was carried out to quantify the variation in CP content within an existing gene pool and develop high throughput techniques for protein determination appropriate to a plant breeding programme

    Residual Stresses Induced in T Butt Welds from Submerged Arc Welding of High Strength Thick Section Steel Members

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    The overall residual stress profiles of a weld fabricated structures such as a submarine pressure hull fabricated using high strength welds joining quench and tempered steels is complex as they are the net profiles from the build-up or relaxation of the residual stresses induced into the welds and structural members from each step in the fabrication process. University of Adelaide with its research partners has attempted to increase the knowledge of residual stresses in this type of structure by undertaking a comprehensive residual stress measurement program using test pieces representing each stage of the fabrication of a submarine pressure hull including full scale test pieces. The primary methods of measuring subsurface residual stress profiles was the neutron diffraction method with the Deep Hole Drilling technique (DHD) to validate key results. The X ray diffraction method and Incremental Centre Hole Drilling methods were used for determining surface residual stresses. This paper presents an overview of the results for residual stress profiles resulting from a full penetration double sided T Butt weld joining a T Frame to a thick flat plate by Submerged Arc Welding. The test piece used a specific pass placement strategy that placed the last pass each side on the base plate. The results presented show that the actual profile is considerably different than those for established fracture mechanics residual stress profiles in that these are over conservative. The discussion will include comparison of results to other measurement results undertaken on similar test pieces but undertaken with an alternate pass placement strategy

    The ion-induced charge-exchange X-ray emission of the Jovian Auroras: Magnetospheric or solar wind origin?

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    A new and more comprehensive model of charge-exchange induced X-ray emission, due to ions precipitating into the Jovian atmosphere near the poles, has been used to analyze spectral observations made by the Chandra X-ray Observatory. The model includes for the first time carbon ions, in addition to the oxygen and sulfur ions previously considered, in order to account for possible ion origins from both the solar wind and the Jovian magnetosphere. By comparing the model spectra with newly reprocessed Chandra observations, we conclude that carbon ion emission provides a negligible contribution, suggesting that solar wind ions are not responsible for the observed polar X-rays. In addition, results of the model fits to observations support the previously estimated seeding kinetic energies of the precipitating ions (~0.7-2 MeV/u), but infer a different relative sulfur to oxygen abundance ratio for these Chandra observations.Comment: 11 pages, 2 figures, 2 tables, submitted to ApJ Lette

    The Anti-social Behaviour, Crime and Policing Act 2014: implications for sex workers and their clients

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    © 2015 Taylor & Francis. The Anti-social Behaviour, Crime and Policing Act 2014 introduced new powers to deal with behaviour deemed to be ‘anti-social’. In this paper we consider how the new law could be used against sex workers and their clients and the impact this may have. Although the new powers were not intentionally designed to respond to prostitution, we suggest that they will be utilised to tackle it. We argue that the law will be used inconsistently in a way which will go directly against policy which seeks to ‘tackle demand’ and take a less punitive approach to dealing with sex workers. Despite a policy shift to see sex workers more as victims and less as offenders, we draw on existing evidence to demonstrate that the new anti-social behaviour order law will be utilised to exclude street sex workers from public spaces. We claim that a degree of ‘policy re-fraction’ will occur when the new laws are implemented by practitioners

    ‘It’s better than daytime television’: questioning the socio-spatial impacts of massage parlours on residential communities

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    It has been shown that street sex work is problematic for some communities, but there is less evidence of the effects of brothels. Emerging research also suggests that impact discourses outlined by residential communities and in regulatory policies should be critiqued, because they are often based on minority community voices, and limited tangible evidence is used to masquerade wider moral viewpoints about the place of sex work. Using a study of residents living in close proximity to brothels in Blackpool, this paper argues that impact is socially and spatially fluid. Impact needs to be evaluated in a more nuanced manner, which is considerate of the heterogeneity of (even one type of) sex work, and the community in question. Brothels in Blackpool had a variety of roles in the everyday socio-spatial fabric; thus also questioning the common assumption that sex work only impacts negatively on residential communities

    Multiplexed Illumina sequencing libraries from picogram quantities of DNA

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    Background: High throughput sequencing is frequently used to discover the location of regulatory interactions on chromatin. However, techniques that enrich DNA where regulatory activity takes place, such as chromatin immunoprecipitation (ChIP), often yield less DNA than optimal for sequencing library preparation. Existing protocols for picogram-scale libraries require concomitant fragmentation of DNA, pre-amplification, or long overnight steps. Results: We report a simple and fast library construction method that produces libraries from sub-nanogram quantities of DNA. This protocol yields conventional libraries with barcodes suitable for multiplexed sample analysis on the Illumina platform. We demonstrate the utility of this method by constructing a ChIP-seq library from 100 pg of ChIP DNA that demonstrates equivalent genomic coverage of target regions to a library produced from a larger scale experiment. Conclusions: Application of this method allows whole genome studies from samples where material or yields are limiting
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