243 research outputs found

    Flexible conformable hydrophobized surfaces for turbulent flow drag reduction

    Get PDF
    In recent years extensive work has been focused onto using superhydrophobic surfaces for drag reduction applications. Superhydrophobic surfaces retain a gas layer, called a plastron, when submerged underwater in the Cassie-Baxter state with water in contact with the tops of surface roughness features. In this state the plastron allows slip to occur across the surface which results in a drag reduction. In this work we report flexible and relatively large area superhydrophobic surfaces produced using two different methods: Large roughness features were created by electrodeposition on copper meshes; Small roughness features were created by embedding carbon nanoparticles (soot) into Polydimethylsiloxane (PDMS). Both samples were made into cylinders with a diameter under 12 mm. To characterize the samples, scanning electron microscope (SEM) images and confocal microscope images were taken. The confocal microscope images were taken with each sample submerged in water to show the extent of the plastron. The hydrophobized electrodeposited copper mesh cylinders showed drag reductions of up to 32% when comparing the superhydrophobic state with a wetted out state. The soot covered cylinders achieved a 30% drag reduction when comparing the superhydrophobic state to a plain cylinder. These results were obtained for turbulent flows with Reynolds numbers 10,000 to 32,500

    Stimulated Emission Tomography: Beyond Polarization

    Full text link
    In this work we demonstrate the use of stimulated emission tomography to characterize a hyper-entangled state generated by spontaneous parametric down-conversion in a CW-pumped source. In particular, we consider the generation of hyper-entangled states consisting of photon pairs entangled in polarisation and path. These results extend the capability of stimulated emission tomography beyond the polarisation degree of freedom, and demonstrate the use of this technique to study states in higher dimension Hilbert spaces

    Sample size for the assessment of soybean inbred populations.

    Get PDF
    In plant breeding programs, the knowledge about the appropriate sample size for the evaluation of populations is very important. A small sample reduces the chance of selecting superior genotypes, whereas a very large sample may lead to unnecessary increases in cost and labor. A population consisting of 192 soybean lines was divided in groups of 24 lines, which were assessed for grain yield in eight randomized complete block experiments. Analyses of variance were performed for each experiment as well as for groups of experiments, resulting in analyses of variance consisting of 24, 48, 72, 96, 120, 144, 168, and 192 lines. As the sample size increased, the width of confidence intervals of parameter estimates decreased, stabilizing with samples of 144 lines. Therefore, an appropriate sample size for the evaluation of soybean inbred populations should contain about 150 lines

    Efeito de um retrocruzamento na média e na variância de uma população de soja.

    Get PDF
    O objetivo desse trabalho foi avaliar a eficiência de um retrocruzamento para o genitor mais produtivo para a obtenção de linhagens superiores para a produção de grãos (PG) em soja, a partir de um cruzamento biparental. Foram avaliadas experimentalmente 100 progênies de cada um dos dois tipos: progênies F2:4 e progênies RC1F3, em diferentes anos e locais, utilizando o delineamento em látice simples duplicado 10x10 (quatro repetições) e parcelas lineares de 2 m espaçadas de 0,5 m, contendo 30 plantas após o desbaste

    A Manifesto for project management research

    Get PDF
    Project management research has evolved over the past five decades and is now a mature disciplinary field investigating phenomena of interest to academics, practitioners and policymakers. Studies of projects and project management practices are theoretically rich and scientifically rigorous. They are practically relevant and impactful when addressing the pursuit of operational, tactical and strategic advancements in the world of organisations. We want to broaden the conversation between project management scholars and other scholars from cognate disciplines, particularly business and management, in a true scholarship of integration and cross-fertilisation. This Manifesto invites the latter scholars to join efforts providing a foundation for further creative, theoretical and empirical contributions, including but not limited to tackling grand challenges such as climate change, pandemics, and global poverty. To this end, we identify five theses: Projects are often ‘agents of change’ and hence fundamental to driving the innovation and change required to tackle grand challenges. Much project management research leverages and challenges theories across disciplines, including business, organisation and management studies, contributing to developing new theories, including those specific to projects and temporary organisations. ‘Projects’ are useful units of analysis, project management research is ideal for scientific cross-fertilisation and project management scholars welcome academics from other communities to engage in fruitful conversations. As in many other fields of knowledge, the project management research community embraces diversity, welcoming researchers of different genders and various scientific and social backgrounds. Historically rooted in ‘problem-solving’ and normative studies, project management research has become open to interpretative and emancipatory research, providing opportunities for other business, management and organisational scholars to advance their knowledge communities

    Intercruzamento em uma população de soja derivada de um retrocruzamento e perspectivas de melhoramento.

    Get PDF
    Os efeitos de uma geração de intercruzamento em uma população de soja foram avaliados através das médias, variâncias genéticas e respostas à seleção, para o caráter produtividade de grãos. A partir de um cruzamento biparental entre duas linhagens foi realizado um retrocruzamento para a linhagem mais produtiva (RC1). Em seguida esta população foi recombinada, dando origem à população de retrocruzamento intercruzada (RC1#). Na sequência foram obtidas progênies de plantas individuas das duas populações (RC1 e RC1#), via autofecundação natural, num total de 118 progênies por população, que correspondem às progênies RC1F2 e RC1#F2. As progênies das duas populações foram avaliadas no ano agrícola de 2008/09, em experimentos em látice 11x11 com quatro repetições. As parcelas foram colhidas em bulk (gerações RC1F3 e RC1#F3) e avaliadas novamente no ano agrícola 2010/11, utilizando o mesmo delineamento experimental e número de repetições. As médias foram similares entre as populações RC1 e RC1# dentro de cada ano; entretanto, houve um acréscimo nas variâncias genéticas nas populações intercruzadas (RC1#F2 e RC1#F3) e, devido a isso, a resposta esperada com seleção foi 39% superior, em média, para estas. Estes resultados ressaltam a importância do intercruzamento em programas que utilizam populações derivadas de retrocruzamentos

    Avaliação de cruzamentos dialélicos para produção de grãos e caracteres agronômicos, e perspectivas de melhoramento em soja.

    Get PDF
    O objetivo deste trabalho foi estimar os parâmetros da capacidade geral e específica de combinação, identificando genitores e combinações promissoras para gerar populações segregantes que atendam a um programa de melhoramento genético de soja no Estado de São Paulo

    Exploring the front-end of project management

    Get PDF
    This paper is a multi-case study exploratory investigation into the earliest stages of projects and their management. We refer to this throughout the paper as the ‘front-end’. We provide a definition of this phase of the project life cycle and conduct a literature review of the various topics that would suggest themselves to be apposite to the front-end. This includes governance and strategy; requirements and technology; estimating; risk and value; people and learning and development. Following this review of literature, we set out the approach taken in the empirical study. The context for the study was the UK, although many of the organizations investigated had a global presence and some of their projects were multinational in nature. We detail the research methods, the multi-case study route taken and the nature of the in-depth interviews with senior project management representatives from nine extremely credible organizations experienced in managing projects. Our findings are presented so as to identify the key set of findings determined after multiple passes of the interview details. These findings reflect both what comprises the front-end of projects and what management does in the front-end. Some of this would be expected of project management, but we found aspects of the front-end management that are not within the normal remit of what is considered to be traditional project management. These findings both reinforce the literature and offer new insights, for example, showing the strong influence of the commercial and economic non-project players in leading or influencing the front-end of projects. A considered set of conclusions are presented together with recommendations for further research
    corecore