2,068 research outputs found

    Lane formation in a system of dipolar microswimmers

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    Using Brownian Dynamics (BD) simulations we investigate the non-equilibrium structure formation of a two-dimensional (2D) binary system of dipolar colloids propelling in opposite directions. Despite of a pronounced tendency for chain formation, the system displays a transition towards a laned state reminiscent of lane formation in systems with isotropic repulsive interactions. However, the anisotropic dipolar interactions induce novel features: First, the lanes have themselves a complex internal structure characterized by chains or clusters. Second, laning occurs only in a window of interaction strengths. We interprete our findings by a phase separation process and simple force balance arguments

    Generic model for tunable colloidal aggregation in multidirectional fields

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    Based on Brownian Dynamics computer simulations in two dimensions we investigate aggregation scenarios of colloidal particles with directional interactions induced by multiple external fields. To this end we propose a model which allows continuous change in the particle interactions from point-dipole-like to patchy-like (with four patches). We show that, as a result of this change, the non-equilibrium aggregation occurring at low densities and temperatures transforms from conventional diffusion-limited cluster aggregation (DLCA) to slippery DLCA involving rotating bonds; this is accompanied by a pronounced change of the underlying lattice structure of the aggregates from square-like to hexagonal ordering. Increasing the temperature we find a transformation to a fluid phase, consistent with results of a simple mean-field density functional theory

    Soziale Reaktionen auf Menschen mit Beeinträchtigungen

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    In folgender Diplomarbeit werden im Allgemeinen die sozialen Reaktionen auf Menschen mit Beeinträchtigungen untersucht. Hierbei geht es vor allem darum, wie soziale Reaktio-nen entstehen, sich Einstellungen generieren und sich Stigmatisierung bildet. Im ersten, theoretischen Teil, werden diese Punkte genauer untersucht, wobei im Speziel-len auf die Reaktionen gegenüber Menschen mit dem Autismus-Spektrum-Syndrom einge-gangen wird. Im zweiten, empirischen Teil, werden vorab die qualitative Methodik samt des inhaltsana-lytischen Auswertungsverfahrens vorgestellt. Für die Untersuchung wurden vier Elternteile von autistischen Kindern, in der Form von Problemzentrierten Interviews, befragt. Im Fo-kus des Interesses standen erfahrene Reaktionen und Bewertungen im nahen/entfernten Umfeld und in der Öffentlichkeit.The underlying thesis is to investigate society's attitudes towards people with disabilities. The main target is to investigate how these attitudes are formed and then how stigmas towards disabilities then result from these attitudes. In the theoretical section the points mentioned above will be investigated in more detail. In particular social attitudes towards people with autism spectrum syndrome will form the central focus area. In the empirical section the methodology used, including a content analytical study, will be discussed. In particular, the research from four parents of autistic children obtained by using a problem- centred interview. The main focus was directed towards their experienced reactions and evaluations within a close and distant social environment and also within a public setting

    NBS Impact Evaluation with GREENPASS Methodology Shown by the Case Study ‘Fischbeker Höfe’ in Hamburg/Germany

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    The implementation of nature-based solutions (NBS) in urban regeneration aims to improve citizens’ health and well-being. Therefore, tools need to be applied to identify the most suitable and efficient location and type of NBS. Within the CLEVER-cities H2020 project, the Greenpass method has been chosen to evaluate different design solutions regarding thermal comfort and physiological equivalent temperature (PET), energy, water and air fluxes. The Greenpass system comprises of standardized tools, reports and a unique set of Key Performance Score (KPS) and Key Performance Indicators (KPI). This paper deals with the impact assessment of NBS by the use of the innovative Greenpass system for the CLEVER-cities project ‘Fischbeker Höfe’ in Hamburg, Germany to ensure human health and well-being improvements for the citizens. To that end and considering the climate change context, thermal comfort is a KPI with high relevance in terms of the NBS co-benefits. Based on the PET within a project area Greenpass calculates the Thermal Comfort Score (TCS). The share of the different PET classes within the project area is multiplied with a weighting factor and summarized to the TCS. The results of the climate resilience analysis of the urban development area ‘Fischbeker Höfe’ in Hamburg are presented and discussed in comparison to a conventional architecture that disregards NBS, showing improvement with regards to four out of five KPS. Based on the evaluation results, advice is given to the co-creative design team on how to further improve the design towards climate resilience. The Greenpass system has proven to be a powerful and tailored tool to support climate resilient urban design and architecture. It provides a standardized and comprehensible but still scientific basis for decisions in a highly efficient and understandable way.This project has been applied in the frame of EU H2020 Project CLEVER-cities funded from the European Union’s Horizon 2020 innovation action program under grant agreement No 776604

    Multidirectional colloidal assembly in concurrent electric and magnetic fields

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Dipolar interactions between nano- and micron sized colloids lead to their assembly into domains with well-defined local order. The particles with a single dipole induced by an external field assemble into linear chains and clusters. However, to achieve the formation of multidirectionally organized nano-or microassemblies with tunable physical characteristics, more sophisticated interaction tools are needed. Here we demonstrate that such complex interactions can be introduced in the form of two independent, non-interacting dipoles (double-dipoles) within a microparticle. We show how this can be achieved by the simultaneous application of alternating current (AC)-electric field and uniform magnetic field to dispersions of superparamagnetic microspheres. Depending on their timing and intensity, concurrent electric and magnetic fields lead to the formation of bidirectional particle chains, colloidal networks, and discrete crystals. We investigate the mechanistic details of the assembly process, and identify and classify the non-equilibrium states formed. The morphologies of different experimental states are in excellent correlation with our theoretical predictions based on Brownian dynamics simulations combined with a structural analysis based on local energy parameters. This novel methodology of introducing and interpreting double-dipolar particle interactions may assist in the assembly of colloidal coatings, dynamically reconfigurable particle networks, and bidirectional active structures.DFG, GRK 1524, Self-Assembled Soft-Matter Nanostructures at Interface

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
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