721 research outputs found

    Soft biomimetic tapered babostructures for large-area antireflective surfaces and SERS sensing

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    Cataloged from PDF version of article.We report a facile fabrication method for the fabrication of functional large area nanostructured polymer films using a drop casting technique. Reusable and tapered silicon molds were utilized in the production of functional polymers providing rapid fabrication of the paraboloid nanostructures at the desired structural heights without the requirement of any complex production conditions, such as high temperature or pressure. The fabricated polymer films demonstrate promising qualities in terms of antireflective, hydrophobic and surface enhanced Raman spectroscopy (SERS) features. We achieved up to 92% transmission from the single-side nanostructured polymer films by implementing optimized nanostructure parameters which were determined using a finite difference time domain (FDTD) method prior to production. Large-area nanostructured films were observed to enhance the Raman signal with an enhancement factor of 4.9 x 10(6) compared to bare film, making them potentially suitable as freestanding SERS substrates. The utilized fabrication method with its demonstrated performances and reliable material properties, paves the way for further possibilities in biological, optical, and electronic applications

    Pluronic polymer capped biocompatible mesoporous silica nanocarriers

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    A facile self-assembly method is described to prepare PEGylated silica nanocarriers using hydrophobic mesoporous silica nanoparticles and a pluronic F127 polymer. Pluronic capped nanocarriers revealed excellent dispersibility in biological media with cyto- and blood compatibilities. © 2013 The Royal Society of Chemistry

    X-Ray Diffraction Studies of Quaternary Ammonium Treated Montmorillonite

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    This study was undertaken to investigate the water-proofing effect of quaternary ammonium ions on montmorillonite. The interaction between a quaternary ammonium ion and montmorillonite was investigated on the basis of basal spacings and electrokinetic behavior of the compound formed

    Oscillating epidemics in a dynamic network model: stochastic and mean-field analysis

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    An adaptive network model using SIS epidemic propagation with link-type-dependent link activation and deletion is considered. Bifurcation analysis of the pairwise ODE approximation and the network-based stochastic simulation is carried out, showing that three typical behaviours may occur; namely, oscillations can be observed besides disease-free or endemic steady states. The oscillatory behaviour in the stochastic simulations is studied using Fourier analysis, as well as through analysing the exact master equations of the stochastic model. By going beyond simply comparing simulation results to mean-field models, our approach yields deeper insights into the observed phenomena and help better understand and map out the limitations of mean-field models

    Moment Closure - A Brief Review

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    Moment closure methods appear in myriad scientific disciplines in the modelling of complex systems. The goal is to achieve a closed form of a large, usually even infinite, set of coupled differential (or difference) equations. Each equation describes the evolution of one "moment", a suitable coarse-grained quantity computable from the full state space. If the system is too large for analytical and/or numerical methods, then one aims to reduce it by finding a moment closure relation expressing "higher-order moments" in terms of "lower-order moments". In this brief review, we focus on highlighting how moment closure methods occur in different contexts. We also conjecture via a geometric explanation why it has been difficult to rigorously justify many moment closure approximations although they work very well in practice.Comment: short survey paper (max 20 pages) for a broad audience in mathematics, physics, chemistry and quantitative biolog

    Finite-size scaling for non-linear rheology of fluids confined in a small space

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    We perform molecular dynamics simulations in order to examine the rheological transition of fluids confined in a small space. By performing finite-size scaling analysis, we demonstrate that this rheological transition results from the competition between the system size and the length scale of cooperative particle motion.Comment: 4pages, 8 figure

    Understanding adhesion at as-deposited interfaces from ab initio thermodynamics of deposition growth: thin-film alumina on titanium carbide

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    We investigate the chemical composition and adhesion of chemical vapour deposited thin-film alumina on TiC using and extending a recently proposed nonequilibrium method of ab initio thermodynamics of deposition growth (AIT-DG) [Rohrer J and Hyldgaard P 2010 Phys. Rev. B 82 045415]. A previous study of this system [Rohrer J, Ruberto C and Hyldgaard P 2010 J. Phys.: Condens. Matter 22 015004] found that use of equilibrium thermodynamics leads to predictions of a non-binding TiC/alumina interface, despite the industrial use as a wear-resistant coating. This discrepancy between equilibrium theory and experiment is resolved by the AIT-DG method which predicts interfaces with strong adhesion. The AIT-DG method combines density functional theory calculations, rate-equation modelling of the pressure evolution of the deposition environment and thermochemical data. The AIT-DG method was previously used to predict prevalent terminations of growing or as-deposited surfaces of binary materials. Here we extent the method to predict surface and interface compositions of growing or as-deposited thin films on a substrate and find that inclusion of the nonequilibrium deposition environment has important implications for the nature of buried interfaces.Comment: 8 pages, 6 figures, submitted to J. Phys.: Condens. Matte

    Sporun toplumsal boyutlarının değerlendirilmesi

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    İnsanların spor yapma alışkanlığını kazanması, yeteneklerinin geliştirilmesi açısından ve sağlıklı kalabilmesi için spor yapmasının gerekli olduğu toplumun her kesimince bilinmektedir. Toplum içerisinde sosyalleşmede bir araç olan spor, fert ve toplum ilişkilerinin geliştirilmesinde de etkili olmaktadır. Bu çalışmanın amacı, spor ve toplum ilişkisi içeriğinde ilgili literatür imkan dahilinde taranıp elde edilen veriler ilişkilendirilerek değerlendirilmiştir. Bu çalışma analitik metot kullanılarak yürütülmüştür. Ferdin spora olan ilgisi ve bağı, toplum içinde yaşama kurallarına uyumu zorunlu hale getirmiştir. Spor fiziksel, ruhsal ve toplumsal gelişimde de önemli bir olgudur. Spor, ferde sabırlı ve enerjik olmayı, sosyal grup ve toplum ile bütünleşmeyi sağlarken, fert ile toplum arası ilişkileri daha ahlaki kılmaktadır. Spor sayesinde insanlar aynı amaçlara yönelmeye, birlikte hareket etme duygusunu yaşamaya başlarlar. Sonuç olarak; insan yaşamı ile bütünleşmiş olan spor, insanların sağlıklı, başarılı mutlu olmasında ve yüksek moral gücüne sahip olmasında çok önemli rol oynamaktadır. Spor, insanın toplumda diğer insanlara ulaşmasında bir unsurdur. Yine insanlar spor sayesinde aynı amaçlara yönelmeye, birlikte hareket etme duygusunu yaşamaya başlarlar. Spor, fiziksel, ruhsal ve toplumsal gelişimde de fayda sağlamaktadır

    An analysis of integrative outcomes in the Dayton peace negotiations

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    The nature of the negotiated outcomes of the eight issues of the Dayton Peace Agreement was studied in terms of their integrative and distributive aspects. in cases where integrative elements were Sound, further analysis was conducted by concentrating on Pruitt's five types of integrative solutions: expanding the pie, cost cutting, non-specific compensation, logrolling, and bridging. The results showed that real world international negotiations can arrive at integrative agreements even when they involve redistribution of resources tin this case the redistribution of former Yugoslavia). Another conclusion was that an agreement can consist of several distributive outcomes and several integrative outcomes produced by different kinds of mechanisms. Similarly, in single issues more than one mechanism can be used simultaneously. Some distributive bargaining was needed in order to determine how much compensation was required. Finally, each integrative formula had some distributive aspects as well

    Monitoring of drinking water distribution system by SCADA in Antalya City, Turkey

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    Antalya water and wastewater administration has recently completed SCADA (Supervisory Control And Data Acquisition) system. The system enabled the on-line continuous monitoring of many water quantity and quality parameters such as flow rate, pressure, temperature, pH, turbidity, electrical conductivity, and free residual chlorine. Additionally, water levels in the distribution reservoirs, water pumps, energy consumption and the closing valves are monitored and controlled by the SCADA system. Beside the on-line continuous monitoring, field sampling and lab analyses of other water quality parameters such as total organic carbon, THM, bromide, iron, nitrogen and phosphorous groups, and coliform bacteria were conducted. The results of field sampling agreed with the on-line monitoring values. The SCADA system proved to be very useful for reducing water losses, improving water quality, reducing energy consumption and improving the reliability of the system
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