1,206 research outputs found

    Effect of Magnetic Field on Entropy Generation in a Microchannel Heat Sink with Offset Fan Shaped

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    In this study, convection flow in microchannel heat sink with offset fan-shaped reentrant cavities in sidewall filled with Fe3O4-water is numerically investigated. The effects of changing some parameters such as Reynolds number and magnetic field are considered. The nanofluid flow is laminar, steady and incompressible, while the thermo-physical properties of nanoparticles were assumed constant. A finite volume method and two phase mixture models were used to simulate the flow. The obtained results show that the frictional entropy generation increases as Reynolds number increases, while a reverse trend is observed for thermal entropy generation. By applying a non-uniform magnetic field, the entropy generation due to heat transfer decreases at first and then increases. When using the uniform magnetic field, the frictional entropy generation and thermal entropy generation is negligible. For all studied cases, the total entropy generation decreases using non-uniform magnetic fields. The results indicate that by increasing the magnetic field power, the total entropy generation decreases

    Is there fame bias in editorial choice?

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    Nature’s Correspondence items are reviewed only by the editors (see go.nature.com/cmchno). To investigate whether editorial bias towards internationally renowned correspondents might be at play in selecting candidates for publication, we analysed the scientific status of Correspondence authors published in 2014. We used the following pointers to gauge author reputation: faculty member in one of the world’s top 100 universities (as listed in the Times Higher Education World University Rankings; see go.nature. com/bhgfxd); authorship of Nature or Science publications; high h index. We classed correspondents as established scholars if they fulfilled any or all of these criteria. The number of letters published in Correspondence in 2014 was 239, each with one ‘corresponding author’ responsible for submission and communication with the editors. We found that 54% of these authors met some or all of our criteria. Some 13% of authors came from the developing world. Within the limitations of our ‘fame factors’ (for example, some correspondents were well known but from outside academia) and of sampling only the corresponding authors, we infer that scientific celebrity does not notably influence the selection of Correspondence for publication

    CCDC 1434838: Experimental Crystal Structure Determination

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    Related Article: Mehdi M. Baradarani, Sahar Khoshsirat, Mehri Moharampour, Bahman Ebrahimisaatlo, Ahmad Rashidi, Ewa Różycka-Sokołowska and John A. Joule|2017|J.Heterocycl.Chem.|54|944|doi:10.1002/jhet.265

    A similarity solution for mixed-convection boundary layer nanofluid flow on an inclined permeable surface

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    This paper concerns with calculation of heat transfer and pressure drop in a mixedconvection nanofluid flow on a permeable inclined flat plate. Solution of governing boundary layer equations is presented for some values of injection/suction parameter (f0), surface angle (Î3), Galileo number (Ga), mixed-convection parameter (λ), volume fraction (Ï), and type of nanoparticles. The numerical outcomes are presented in terms of average skin friction coefficient (Cf) and Nusselt number (Nu). The results indicate that adding nanoparticles to the base fluid enhances both average friction factor and Nusselt number for a wide range of other effective parameters. We found that for a nanofluid with Ï=0.6, injection from the wall (f0=0.2) offers an enhancement of 30% in Cf than the base fluid, while this growth is about 35% for the same case with wall suction (f0=0.2). However, increasing the wall suction will linearly raise the heat transfer rate from the surface, similar for all range of nanoparticles volume fraction. The computations also showed that by changing the surface angle from horizontal state to 60 deg, the friction factor becomes 2.4 times by average for all Ï's, while 25% increase yields in Nusselt number for the same case. For assisting flow, there is a favorable pressure gradient due to the buoyancy forces, which results in larger Cf and Nu than in opposing flows. We can also see that for all u values, enhancing Ga/Re2 parameter from 0 to 0.005 makes the friction factor 4.5 times, while causes 50% increase in heat transfer coefficient. Finally, we realized that among the studied nanoparticles, the maximum influence on the friction and heat transfer belongs to copper nanoparticles

    Analytical Modeling of MHD Flow over a Permeable Rotating Disk in the Presence of Soret and Dufour Effects: Entropy Analysis

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    The main concern of the present article is to study steady magnetohydrodynamics (MHD) flow, heat transfer and entropy generation past a permeable rotating disk using a semi numerical/analytical method named Homotopy Analysis Method (HAM). The results of the present study are compared with numerical quadrature solutions employing a shooting technique with excellent correlation in special cases. The entropy generation equation is derived as a function of velocity, temperature and concentration gradients. Effects of flow physical parameters including magnetic interaction parameter, suction parameter, Prandtl number, Schmidt number, Soret and Dufour number on the fluid velocity, temperature and concentration distributions as well as entropy generation number are analysed and discussed in detail. Results show that increasing the Soret number or decreasing the Dufour number tends to decrease the temperature distribution while the concentration distribution is enhanced. The averaged entropy generation number increases with increasing magnetic interaction parameter, suction parameter, Prandtl number, and Schmidt number

    Supplemental Material - Pre-Hospital and Post-Hospital Quality of Care in Traumatic Spinal Column and Cord Injuries in Iran

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    Supplemental Material for Pre-Hospital and Post-Hospital Quality of Care in Traumatic Spinal Column and Cord Injuries in Iran by Arman Zeinaddini-Meymand, Vali Baigi, Mehdi Mousavi-Nasab, Sina Shool, Mohsen Sadeghi-Naini, Zahra Azadmanjir, Seyed Behnam Jazayeri, Samuel Berchi Kankam, Mohammad Dashtkoohi, Aidin Shakeri, Esmail Fakharian, Leila Kouchakinejad-Eramsadati, Habibollah Pirnejad, Homayoun Sadeghi-Bazargani, Laleh Bagheri, Yasaman Pourandish, Malihe Amiri, Ahmad Pour-Rashidi, James Harrop, and Vafa Rahimi-Movaghar in Global Spine Journal</p

    Application of Analog Adaptive Filters for Dynamic Sensor Compensation

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    This paper investigates the application of analog adaptive techniques to the area of dynamic sensor compensation, of which there is little reported work in the literature. The case is illustrated by showing how the response of a load cell can be improved to speed up the process of measurement. The load cell is a sensor with an oscillatory output in which the measurand contributes to the response parameters. Thus, a compensation filter needs to track variation in measurand whereas a simple, fixed filter is only valid at one specific load value. To facilitate this investigation, computer models for the load cell and the adaptive compensation filter have been developed. To allow a practical implementation of the adaptive techniques, a novel piecewise linearization technique is proposed in order to vary a floating voltage-controlled resistor in a linear manner over a wide range. Simulation and practical results are presented, thus demonstrating the effectiveness of the proposed techniques

    Branding the 'Beur' Author Minority Writing and the Media in France

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    This book reconsiders authorship by the descendants of North African immigrants to France by consulting how these authors' novels have been discussed and promoted in the national audio-visual media.Cover -- Contents -- Acknowledgements -- List of Illustrations -- 1. Authorship at a Crossroads -- 2. Mehdi Charef and the Invention of Beur Writing -- 3. Competing Visions of Minority Authorship -- 4. Eyewitness Narratives and the Creation of the Beurette -- 5. Rachid Djaïdani and the Shift from Beur to Banlieue Writing -- 6. Revising the Beurette Label -- 7. Sabri Louatah and the Collectif Qui Fait la France? -- Works Cited -- IndexThis book reconsiders authorship by the descendants of North African immigrants to France by consulting how these authors' novels have been discussed and promoted in the national audio-visual media.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries

    A new, 3D overlapping-sphere model of cell adhesion:

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    Cell adhesion refers to the ability of cells to make enduring and dynamic attachments to extracellular surfaces and to each other; rightly so it is a focal point of current biological research. I have designed a computational framework to model cell adhesion using a modified overlapping-sphere model. A core feature of the model is the three-dimensional representation of a cell surface that can interact mechanically with its environment. The generalization of a cell as a sphere gives our model the compactness to enable the simulations of thousands of cells, comparable to the number of cells typically encountered through small scale studies of early development and disease. Specifically, we use this computational framework to model adhesion between cells in a monolayer and a fibrous environment, cell shape change, as well as cell replication. We also include elements of cell orientation, or cell polarity, and touch on some aspects of mechanical feedback. We explore some general aspects of developmental biology as well as cancer in mammary ducts. Although we emphasize epithelial cells, which are cells that form monolayers, we also briefly consider migratory cells. The major results are that (1) Cells in a monolayer, like sheets and tubes, need to be both mobile and well-connected to adapt to mechanically stresses, (2) Cells that are not polarized do not produce a stable monolayer of cells, (3) Extracellular support, like a basement membrane, can minimize the stresses experienced at cell-cell junctions, (4) Mitosis triggered by tension can help maintain a monolayer of cells, (5) Cell shape needs to be incorporated into models to minimize undesirable stresses, (6) Our computational framework is useful to predict behavior of cells subjected to mechanical forces. As this is a new model, results are chiefly qualitative, and suggest future work in collaboration with experimentalists to verify and quantitate our results.M.S.Includes bibliographical references (p. 79-81)by Mehdi Doum

    Correction: Synthesis and characterization of a new ZIF-67@MgAl 2 O 4 nanocomposite and its adsorption behaviour

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    Publisher Copyright: © 2021 The Royal Society of Chemistry.The authors regret that an incorrect affiliation was given for co-author Mehdi Bazarganipour in the original article. The correct affiliations are as shown here. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers
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