Zuschreibungen in Freundschaftserzählungen

Die vorliegende empirische Arbeit befasst sich mit Freundschaften, zwischen muslimischen Frauen türkischer Herkunft und Frauen nicht-türkischer Herkunft. Die Ergebnisse basieren auf zehn narrativen Interviews, die mit hermeneutischen Verfahren ausgewertet wurden. Interviewt wurden sowohl türkische, muslimische Migrantinnen der zweiten Generation als auch Migrantinnen der zweiten Generation, nicht-türkischer Herkunft und Frauen österreichischer Herkunft. In den Interviews wurden Frauen türkischer Herkunft aufgefordert über ihre Freundschaft zu einer Freundin österreichischer Herkunft zu erzählen. Ebenso wurden Frauen österreichischer Herkunft und Migrantinnen nicht-türkischer Herkunft zu ihren Freundschaften mit Musliminnen türkischer Herkunft befragt. Im Zentrum der Untersuchung stand die Frage nach unterschiedlichen Zuschreibungen, die in den Narrationen thematisiert wurden, und die sich auf das Verhältnis zwischen Mehrheitsgesellschaft und Minderheit rückführen lassen. Dabei stehen diese Zuschreibungen auch immer in Zusammenhang mit Identitäten und Zugehörigkeiten der jeweiligen Erzählerin. Bei den Interviewpartnerinnen türkischer Herkunft als auch bei denjenigen mit nicht-türkischem Migrationshintergrund sind Mehrfachzugehörigkeiten gegeben. Die vorliegende Arbeit hat ihren Ausgangspunkt in Freundschaften zwischen Mitgliedern der Mehrheit und Minderheit. Die Beziehungen zwischen Musliminnen türkischer Herkunft und Frauen nicht-türkischer Herkunft unterscheiden sich hinsichtlich Intensität, Dauer und Aktivitäten von den Freundschaften, die sie in ihrem 'Hauptfreundeskreis' pflegen. Die islamische Religionszugehörigkeit spielt insofern eine Rolle, als dass am Beginn der Freundschaft viel Aufklärungs- und Rechtfertigungsbedarf der Musliminnen gegenüber ihren nicht-muslimischen Freundinnen besteht. Hintergründe für die Freundschaftswahlen, unterschiedliche Zuschreibungen und Identitäten bzw. Zugehörigkeiten stehen daher im Mittelpunkt der Arbeit

Efficient Simulation Method for Parallel Tube Evaporators for Vehicle Battery Cooling

Due to its size, the cooling of a vehicle battery by means of a refrigeration system has to be implemented e.g. via parallel evaporator tubes. After the throttle, the two-phase refrigerant flow must be uniformly distributed into several cooling channels so that uniform cooling can be achieved throughout the entire volume. The simulation of the three-dimensional effects in the distributor and also in the collector of an evaporator with several parallel evaporator tubes can only be done by computational fluid dynamics (3D CFD). However, the 3D CFD simulation of the evaporator is time consuming and can be replaced by a 1D calculation applying simple correlations for pressure losses and heat transfer coefficients (HTCs). The 1D model approach is implemented by a script that runs within the commercial software of the industrial partner for a parallel tube evaporator geometry. The CFD simulation is based on a Eulerian multiphase approach where both phases are modelled as continuous fluids and all conservation equations are solved for each of these phases. The evaporator tubes are discretised in the direction of the tube in order to get the distribution of the variables in longitudinal direction. The used refrigerant is R134a. In this work, an evaporator consisting of a distributor, a collector and four parallel evaporator tubes that were led at right angles to them was investigated. All these components are located in a plane. This geometry has been chosen in accordance with tests carried out. The focus of this paper is the coupling method, the simplification that has been made and the efficiency of the simulation. A comparison between simulation and test bench measurements shows deviations in the total mass flow distribution in the order of less than 10%. Liquid and vapor mass distribution show larger deviations in the order of 20-50% in different operating conditions. Possible improvements can be achieved by varying influencing factors in the CFD-simulation, e.g. the droplet diameter. Finally, the results are analysed for the variation of two parameters. The method is also applicable to geometric variations of heat exchangers

Análisis de un convertidor de par

El convertidor de par es un elemento hidrodinámico que se utiliza para transmitir, de una forma suave, la potencia del motor a la transmisión. Es un excelente elemento en la generación efectiva de par en condiciones severas de trabajo aunque presenta una eficiencia bastante deficiente. Por ello su diseño es un aspecto importante, ya que la geometría y curvatura de los álabes afectan al comportamiento del flujo, y como consecuencia a su rendimiento. Por otro lado,realizar investigaciones experimentales de mejora de dicho componente resulta caro y complicado. Este proyecto muestra un análisis de un convertidor de par en cuanto a los aspectos que van ligados directamente con la eficiencia del mismo, y que como bien se han mencionado, son los relativos a la geometría y al comportamiento del flujo interno. Así, se ha desarrollado una práctica herramienta de Excel para la empresa AVL List GmbH, lugar en el que se ha desarrollado este proyecto, que permite a un diseñador calcular y construir un convertidor de par aceptablemente competitivo. Además, se ha analizado su flujo interno, mediante técnicas de CFD utilizando el software AVL FIRE ®, para afirmar si realmente es una herramienta viable para predecir las características y evaluar el rendimiento de un convertidor de par

Experimental Investigation of Liquid and Vapor Mass Flows in a Parallel Tube Evaporator

One of the major challenges in the evaluation of an evaporator heat exchanger in refrigeration cycles is to provide reasonable measurement data. Especially if the evaporator is multi-flow and therefore the measurement of the mass flow at one location and the evaluation of the overall energy balance is not sufficient for the characterization of the heat exchanger. In the present work, an evaporator of a capacity of approx. 1.2 kW, consisting of a distributor, a collector and four parallel evaporator tubes in which heat was introduced, was experimentally investigated. The four evaporator tubes made of stainless steel with an inner diameter of 2 mm, an outer diameter of 4 mm and a length of 800 mm were led out of the distributor and into the collector at a right angle at a distance of 90 mm from each other. All tubes form a plane. To keep the geometry of the joints as uniform as possible, commercially available fittings were used. The evaporator was investigated as part of a refrigeration cycle with several adjustment possibilities like mass flow, subcooling, and pressure. To determine the mass flow and vapor quality distribution within the heat exchanger, each evaporator tube was divided into two heating sections of 400 mm and 200 mm length respectively with an intermediate measuring section of 200 mm for pressure and temperature. The first sections were heated by variable electrical heat loads, uniformly distributed over a length of 345 mm. The heat load was adjusted so that a slight superheating of approx. 4 K occurred at the outlet. In the second sections a constant electrical heat load was uniformly applied over a length of 150 mm. Assuming that a thermal equilibrium between the phases in the first sections is established, the heat loads can be used to draw conclusions about the respective mass flows of liquid refrigerant. In the second sections, the constant heat flow can be used to draw conclusions about the different total mass flows due to the different outlet temperatures. The measurements were carried out in our own laboratory for different vapor qualities from x=0 to x=0.3 and different overall total mass flows of the cycle ranging from 5, 7.5 and 10 kg/h to partly 20 kg/h. During the measurements, different inclinations of the evaporator relative to the horizontal plane were realized as well, so that a large number of measurement results were finally recorded. The measurement setup allows the evaluation of liquid and vapor refrigerant mass flow rates in each evaporator channel and makes a comparison between the sum of the four individual total mass flow rates and the overall total mass flow rate of the cycle possible. The results show the influence of the variable gravity vector and flow velocity on the distribution. In the horizontal measuring point the tube furthest away from the distributor inlet exhibits the highest vapor quality of all 4 tubes, contrary to what was expected. Finally, the results are used to validate the simulation models of the industrial project partner

ConfusionFlow: A Model-Agnostic Visualization for Temporal Analysis of Classifier Confusion

Classifiers are among the most widely used supervised machine learning algorithms. Many classification models exist, and choosing the right one for a given task is difficult. During model selection and debugging, data scientists need to assess classifiers' performances, evaluate their learning behavior over time, and compare different models. Typically, this analysis is based on single-number performance measures such as accuracy. A more detailed evaluation of classifiers is possible by inspecting class errors. The confusion matrix is an established way for visualizing these class errors, but it was not designed with temporal or comparative analysis in mind. More generally, established performance analysis systems do not allow a combined temporal and comparative analysis of class-level information. To address this issue, we propose ConfusionFlow, an interactive, comparative visualization tool that combines the benefits of class confusion matrices with the visualization of performance characteristics over time. ConfusionFlow is model-agnostic and can be used to compare performances for different model types, model architectures, and/or training and test datasets. We demonstrate the usefulness of ConfusionFlow in a case study on instance selection strategies in active learning. We further assess the scalability of ConfusionFlow and present a use case in the context of neural network pruning

Evidenzbasierte Leseförderung in der Grundschule: Vorstellung einer Interventionsstudie

Im Beitrag werden erste Ergebnisse eines Forschungsprojekts dargestellt, das durch das Bundesministerium für Bildung und Forschung (BMBF) im Rahmen der Forschungsinitiative "Ursachenbezogene individuelle Diagnostik und Intervention bei umschriebenen Entwicklungsstörungen schulischer Fertigkeiten" gefördert worden ist. Das Ziel des Strategietrainings ist die Förderung des Sinn entnehmenden, strategischen Lesens, also die Stärkung lokaler und globaler Kohärenzbildungsprozesse. Die Durchführbarkeit der Lesetrainings ist in einer Pilotierungsuntersuchung mit 328 Kindern erprobt worden. Die Ergebnisse sprechen für lesespezifische Trainingseffekte auf die Dekodierleistung: Das Fluency- und Strategietraining führten in der zweiten Klassenstufe zu deutlichen Verbesserungen, wobei die Wirksamkeit der Trainings auf das Leseverstehen durch die Effizienz kognitiver Teilprozesse des Lesens moderiert zu sein scheint. Die Interaktion verläuft zu Gunsten der Kinder mit ineffizienten Teilprozessen der visuellen Worterkennung, die stärker vom Training profitieren konnten. Innerhalb der vierten Klassenstufe haben sich Fluency- und Phonicstraining als effektiv erwiesen. Auf Grund der zum Teil signifikanten Unterschiede in den Vortestwerten können die Ergebnisse jedoch nur unter Vorbehalt interpretiert werden. (ICF2

An international collaborative evaluation of central serous chorioretinopathy: different therapeutic approaches and review of literature. The European Vitreoretinal Society central serous chorioretinopathy study

Purpose: To study and compare the efficacy of different therapeutic options for the treatment of central serous chorioretinopathy (CSCR). Methods: This is a nonrandomized, international multicentre study on 1719 patients (1861 eyes) diagnosed with CSCR, from 63 centres (24 countries). Reported data included different methods of treatment and both results of diagnostic examinations [fluorescein angiography and/or optical coherent tomography (OCT)] and best-corrected visual acuity (BCVA) before and after therapy. The duration of observation had a mean of 11 months but was extended in a minority of cases up to 7 years. The aim of this study is to evaluate the efficacy of the different therapeutic options of CSCR in terms of both visual (BCVA) and anatomic (OCT) improvement. Results: One thousand seven hundred nineteen patients (1861 eyes) diagnosed with CSCR were included. Treatments performed were nonsteroidal anti-inflammatory eye drops, laser photocoagulation, micropulse diode laser photocoagulation, photodynamic therapy (PDT; Standard PDT, Reduced-dose PDT, Reduced-fluence PDT), intravitreal (IVT) antivascular endothelial growth factor injection (VEGF), observation and other treatments. The list of the OTHERS included both combinations of the main proposed treatments or a variety of other treatments such as eplerenone, spironolactone, acetazolamide, beta-blockers, anti-anxiety drugs, aspirin, folic acid, methotrexate, statins, vitis vinifera extract medication and pars plana vitrectomy. The majority of the patients were men with a prevalence of 77%. The odds ratio (OR) showed a partial or complete resolution of fluid on OCT with any treatment as compared with observation. In univariate analysis, the anatomical result (improvement in subretinal fluid using OCT at 1 month) was favoured by age <60 years (p < 0.005), no previous observation (p < 0.0002), duration less than 3 months (p < 0.0001), absence of CSCR in the fellow eye (p = 0.04), leakage outside of the arcade (p = 0.05) and fluid height >500 \u3bcm (p = 0.03). The OR for obtaining partial or complete resolution showed that anti-VEGF and eyedrops were not statistically significant; whereas PDT (8.5), thermal laser (11.3) and micropulse laser (8.9) lead to better anatomical results with less variability. In univariate analysis, the functional result at 1 month was favoured by first episode (p = 0.04), height of subretinal fluid >500 \u3bcm (p < 0.0001) and short duration of observation (p = 0.02). Finally, there was no statistically significant difference among the treatments at 12 months. Conclusion: Spontaneous resolution has been described in a high percentage of patients. Laser (micropulse and thermal) and PDT seem to lead to significant early anatomical improvement; however, there is little change beyond the first month of treatment. The real visual benefit needs further clarification

Thermal slip and radiative heat transfer effects on electro-osmotic magnetonanoliquid peristaltic propulsion through a microchannel

A mathematical study is described to examine the concurrent influence of thermal radiation and thermal wall slip on the dissipative magnetohydrodynamic electro-osmotic peristaltic propulsion of a viscous nano-liquid in an asymmetric microchannel under the action of an axial electric field and transverse magnetic field. Convective boundary conditions are incorporated in the model and the case of forced convection is studied i.e. thermal and species (nanoparticle volume fraction) buoyancy forces neglected. The heat source and sink effects are also included and the diffusion flux approximation is employed for radiative heat transfer. The transport model comprises the continuity, momentum, energy, nanoparticle volume fraction and electric potential equations with appropriate boundary conditions. These are simplified by negating the inertial forces and invoking the Debye–Hückel linearization. The resulting governing equations are reduced into a system of non-dimensional simultaneous ordinary differential equations, which is solved analytically. Numerical evaluation is conducted with symbolic software (MATLAB). The impact of different control parameters (Hartmann number, electroosmosis parameter, slip parameter, Helmholtz-Smoluchowski velocity, Biot numbers, Brinkman number, thermal radiation and Prandtl number) on the heat, mass and momentum characteristics (velocity, temperature, Nusselt number etc.) are presented graphically. Increasing Brinkman number is found to elevate temperature magnitudes. For positive Helmholtz-Smoluchowski velocity (reverse axial electrical field) temperature is strongly reduced whereas for negative Helmholtz-Smoluchowski velocity (aligned axial electrical field) it is significantly elevated. With increasing thermal slip nanoparticle volume fraction is also increased. Heat source elevates temperatures whereas heat sink depresses them, across the micro-channel span. Conversely, heat sink elevates nano-particle volume fraction whereas heat source decreases it. Increasing Hartmann (magnetic) parameter and Prandtl number enhance the nano-particle volume fraction. Furthermore, with increasing radiation parameter the Nusselt number is reduced at the extremities of the micro-channel whereas it is elevated at intermediate distances. The results reported provide a good insight into biomimetic energy systems exploiting electromagnetics and nanotechnology and furthermore they furnish a useful benchmark for experimental and more advanced computational multi-physics simulations