9,078 research outputs found

    The microbial zoo in the C. elegans intestine: Bacteria, fungi and viruses

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    Press freedom has become one of the major challenges facing Journalism practice in the world. This paper explores the factors hindering press freedom in Nigeria using some relevant examples. The researcher used the qualitative method of research; using secondary data comprising of books and journals. The study is embedded on social responsibility theory. The study reveals that there are a lot of factors in Nigeria that hinders press freedom ranging from secrecy, legal pressure, direct censorship and force among others. Findings also reveal that Nigerian press freedom is a paradox and only exist on paper i.e. in the constitution but not in practice. The study recommends that since press freedom is granted in the constitution of Nigeria, there should be statutory backup and in order not to hinder press freedom, journalist should be allowed to have access to government sources and records so long as it will not bring chaos to the society at large

    Orientation-dependent indentation response of helium-implanted tungsten

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    A literature review of studies investigating the topography of nano-indents in ion-implanted materials reveals seemingly inconsistent observations, with report of both pile-up and sink-in. This may be due to the crystallographic orientation of the measured sample point, which is often not considered when evaluating implantation-induced changes in the deformation response. Here we explore the orientation dependence of spherical nano-indentation in pure and helium-implanted tungsten, considering grains with , and out-of-plane orientations. Atomic force microscopy (AFM) of indents in unimplanted tungsten shows little orientation dependence. However, in the implanted material a much larger, more localised pile-up is observed for grains than for and orientations. Based on the observations for grains, we hypothesise that a large initial hardening due to helium-induced defects is followed by localised defect removal and subsequent strain softening. A crystal plasticity finite element model of the indentation process, formulated based on this hypothesis, accurately reproduces the experimentally-observed orientation-dependence of indent morphology. The results suggest that the mechanism governing the interaction of helium-induced defects with glide dislocations is orientation independent. Rather, differences in pile-up morphology are due to the relative orientations of the crystal slip systems, sample surface and spherical indenter. This highlights the importance of accounting for crystallographic orientation when probing the deformation behaviour of ion-implanted materials using nano-indentation

    Energy saving potential of a counter-flow regenerative evaporative cooler for various climates of China: Experiment-based evaluation

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    © 2017 Recently there has been growing interest in regenerative evaporative coolers (REC), which can reduce the temperature of the supply air to below the wet-bulb of intake air and approach its dew-point. In this paper, we designed, fabricated and experimentally tested a counter-flow REC in laboratory. The REC's core heat and mass exchanger was fabricated using stacked sheets composed of high wicking evaporation (wickability of available materials was measured) and waterproof aluminium materials. The developed REC system has a much higher cooling performance compared to conventional indirect evaporative cooler. However, the decision to use the REC for China buildings depends on a dedicated evaluation of the net energy saved against the capital expended. Such an evaluation requires the hourly-based data on the availability of cooling capacity provided by the REC for various climates. The paper used an experiment-based method to estimate the cooling capacity and energy savings provided by the proposed REC for China's various climates. By using the experimental results and regional hourly-based weather data, the energy saving potential of the REC against an equivalent-sized mechanical air conditioner alone was analysed. The results indicate that, for all selected regions, the REC could reduce 53–100% of cooling load and 13–58% of electrical energy consumption annually

    China's Economy and Market

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    Hongbing Deng's article on China's economy and markets
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