10,155 research outputs found

    Experimental Validation of Multiphase Flow Models and Testing of Multiphase Flow Meters: A Critical Review of Flow Loops Worldwide

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    Around the world, research into multiphase flow is performed by scientists with hugely diverse backgrounds: physicists, mathematicians and engineers from mechanical, nuclear, chemical, civil, petroleum, environmental and aerospace disciplines. Multiphase flow models are required to investigate the co-current or counter-current flow of different fluid phases under a wide range of pressure and temperature conditions and in several different configurations. To compliment this theoretical effort, measurements at controlled experimental conditions are required to verify multiphase flow models and assess their range of applicability, which has given rise to a large number of multiphase flow loops around the world. These flow loops are also used intensively to test and validate multiphase flow meters, which are devices for the in-line measurement of multiphase flow streams without separation of the phases. However, there are numerous multiphase flow varieties due to differences in pressure and temperature, fluids, flow regimes, pipe geometry, inclination and diameter, so a flow loop cannot represent all possible situations. Even when experiments in a given flow loop are believed to be sufficiently exhaustive for a specific study area, the real conditions encountered in the field tend to be very different from those recreated in the research facility. This paper presents a critical review of multiphase flow loops around the world, highlighting the pros and cons of each facility with regard to reproducing and monitoring different multiphase flow situations. The authors suggest a way forward for new developments in this area

    A simple variational method for calculating energy and quantum capacitance of an electron gas with screened interactions

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    We describe a variational procedure for calculating the energy of an electron gas in which the long-range Coulomb interaction is truncated by the screening effect of a nearby metallic gate. We use this procedure to compute the quantum capacitance of the system as a function of electron density and spin polarization. The accuracy of the method is verified against published Monte-Carlo data. The results compare favorably with a recent experiment.Comment: 4 pages, 3 figure

    The leading women: The media representation of minor party leadership during the 2019 UK General Election

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    This thesis analyses the media representation of Nicola Sturgeon, Jo Swinson, and Arlene Foster during the 2019 UK General Election. Each politician within this thesis was serving in a different political system enabling an expansive look at the representation of political leadership across the UK. I examined newspapers, Twitter, and the televised election debates to review the self-presentation and representation of these three female politicians in mediated spaces. Amongst my selection of media, I reviewed the personal Twitter accounts of these political women, their media representation in London-based, Scottish, and Northern Irish national publications, and the televised debates broadcasted on the BBC, ITV, STV, and Channel 4. I analysed these three forms of media by using a mixed methods approach combining content analysis and critical discourse analysis. In this study, there were interesting differences between the three women in terms of explicitly gendered coverage: Foster's coverage was the least gendered, Swinson's the most. At the same time, the media representation of Sturgeon included gendered commentary that was positive in tone and used to present her as politically accomplished. The second prominent finding of the study was the variation in coverage between London-based, Scottish, and Northern Irish newspapers for each politician’s media representation. In addition, each party leader held political positions in different countries of the UK, revealing expressions of banal nationalism within their self-presentation. Notably, the reference to national belonging was most impactful in my Foster and Northern Irish datasets. Foster's selfpresentation and media representation were often focused on Northern Irish issues rather than the whole of the UK. Foster's prominence as a local figure in Northern Ireland and her constituency showed that various methods of analysis are needed to study politicians less prominent in a UK-wide election compared to political figures like Sturgeon and Swinson, who became a part of the national media agenda.This thesis analyses the media representation of Nicola Sturgeon, Jo Swinson, and Arlene Foster during the 2019 UK General Election. Each politician within this thesis was serving in a different political system enabling an expansive look at the representation of political leadership across the UK. I examined newspapers, Twitter, and the televised election debates to review the self-presentation and representation of these three female politicians in mediated spaces. Amongst my selection of media, I reviewed the personal Twitter accounts of these political women, their media representation in London-based, Scottish, and Northern Irish national publications, and the televised debates broadcasted on the BBC, ITV, STV, and Channel 4. I analysed these three forms of media by using a mixed methods approach combining content analysis and critical discourse analysis. In this study, there were interesting differences between the three women in terms of explicitly gendered coverage: Foster's coverage was the least gendered, Swinson's the most. At the same time, the media representation of Sturgeon included gendered commentary that was positive in tone and used to present her as politically accomplished. The second prominent finding of the study was the variation in coverage between London-based, Scottish, and Northern Irish newspapers for each politician’s media representation. In addition, each party leader held political positions in different countries of the UK, revealing expressions of banal nationalism within their self-presentation. Notably, the reference to national belonging was most impactful in my Foster and Northern Irish datasets. Foster's selfpresentation and media representation were often focused on Northern Irish issues rather than the whole of the UK. Foster's prominence as a local figure in Northern Ireland and her constituency showed that various methods of analysis are needed to study politicians less prominent in a UK-wide election compared to political figures like Sturgeon and Swinson, who became a part of the national media agenda

    Combining ability for maize grain yield and other agronomic characters in a typical southern guinea savanna ecology of Nigeria

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    Field experiments were conducted at the University of Ilorin Teaching and Research Farm in 2005 and 2006 cropping seasons with the objective to evaluate the combining ability for maize grain yield andother agronomic characters in 10 open pollinated maize varieties, which have been selected for high yield and stress tolerance. General combining ability (gca) and year (y) effects were significant for allthe parameters except plant height, while specific combining ability (sca) and gca x year effects were significant only for grain yield. However, Tze Comp4 Dmr Srbc2, Tze Comp4 C2 and Acr 94 Tze Comp5 which are good general combiners for maize grain yield, also showed positive significant gca x year effects for flowering traits. Significant sca x year interaction effects were recorded for maize grain yield and days to flowering, with Hei 97 Tze Comp3 C4 combining very well with 3 parents (Acr 90 Pool 16-Dt, Tze Comp4-Dmr Srbc2 and Tze Comp4 C2). These parents and their hybrids probably have genes thatcan be introgressed into other promising lines in developing early maturing and high yielding varieties for cultivation in the Nigeria savannas
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