Benutzerinteraktion in dienstorientierten Architekturen

Ziel der Arbeit ist es, im Rahmen bestehender Entwicklungsvorgehen zur dienstorientierten Unterstützung von Geschäftsprozessen die Anforderungen des Menschen als Benutzer der IT von der Analyse bis zur Implementierung integriert berücksichtigen zu können. Hierbei kommen die Prinzipien der modellgetriebenen Softwareentwicklung zum Einsatz, um (1) eine plattformunabhängige Spezifikation dieser Anforderungen und (2) eine automatisierte Erzeugung der entsprechenden Softwareartefakte zu ermöglichen

TREFF: Reflectometer and instrument component test beamline at MLZ

TREFF is a high resolution polarized neutron reflectometer and instrument component test beamline resulting in a highly modular instrument providing a flexible beam line for various applications

Reversible sodiation of electrochemically deposited binder- and conducting additive-free Si-O-C composite layers

Binder- and conducting additive-free Si-O-C composite layers are deposited electrochemically under potentiostatic conditions from sulfolane-based organic electrolyte. Quartz crystal microbalance with damping monitoring is used for evaluation of the layer growth and its physical properties. The sodiation-desodiation performance of the material is afterward explored in Na-ion electrolyte. In terms of specific capacity, rate capability, and long-term electrochemical stability, the experiments confirm the advantages of applying the electrochemically formed Si-O-C structure as anode for Na-ion batteries. The material displays high (722 mAh g^-1) initial reversible capacity at j = 70 mA g^-1 and preserves stable long-term capacity of 540 mAh g^-1 for at least 400 galvanostatic cycles, measured at j = 150 mA g^-1. The observed high performance can be attributed to its improved mechanical stability and accelerated Na-ion transport in the porous anode structure. The origin of the material electroactivity is revealed based on X-Ray photoelectron spectroscopic analysis of pristine (as deposited), sodiated, and desodiated Si-O-C layers. The evaluation of the spectroscopic data indicates reversible activity of the material due to the complex contribution of carbon and silicon redox centers

Visualisierung der genotypischen Struktur partiell allogamer Populationen und züchterische Konsequenzen

Es wird die Populationsstruktur und daraus resultierende Konsequenzen für die Züchtung partiell allogamer Kulturpflanzen dargestellt

Accurate Distances Measures and Machine Learning of the Texture-Property Relation for Crystallographic Textures Represented by One-Point Statistics

The crystallographic texture of metallic materials is a key microstructural feature that is responsible for the anisotropic behavior, e.g., important in forming operations. In materials science, crystallographic texture is commonly described by the orientation distribution function, which is defined as the probability density function of the orientations of the monocrystal grains conforming a polycrystalline material. For representing the orientation distribution function, there are several approaches such as using generalized spherical harmonics, orientation histograms, and pole figure images . Measuring distances between crystallographic textures is essential for any task that requires assessing texture similarities, e.g. to guide forming processes. Therefore, we introduce novel distance measures based on (i) the Earth Movers Distance that takes into account local distance information encoded in histogram-based texture representations and (ii) a distance measure based on pole figure images. For this purpose, we evaluate and compare existing distance measures for selected use-cases. The present study gives insights into advantages and drawbacks of using certain texture representations and distance measures with emphasis on applications in materials design and optimal process control

Technical light-field setup for 3D imaging of the human nerve head validated with an eye model

With the new technology of 3D light field (LF) imaging, fundus photography can be expanded to provide depth information. This increases the diagnostic possibilities and additionally improves image quality by digitally refocusing. To provide depth information in the human optic nerve head such as in glaucoma diagnostics, a mydriatic fundus camera was upgraded with an LF imager. The aim of the study presented here was the validation of the technical setup and resulting depth estimations with an appropriate eye model. The technical setup consisted of a mydriatic fundus camera (FF450, Carl Zeiss Meditec AG, Jena, Germany) and an LF imager (R12, Raytrix GmbH, Kiel, Germany). The field of view was set to 30°. The eye model (24.65 mm total length) consisted of a two-lens optical system and interchangeable fundus models with papilla excavations from 0.2 to 1 mm in steps of 0.2 mm. They were coated with red acrylic lacquer and vessels were drawn with a thin brush. 15 images were taken for each papilla depth illuminated with green light (wavelength 520 nm ± 20 nm). Papilla depth was measured from the papilla ground to the surrounding flat region. All 15 measurements for each papilla depth were averaged and compared to the printed depth. It was possible to perform 3D fundus imaging in an eye model by means of a novel LF-based optical setup. All LF images could be digitally refocused subsequently. Depth estimation in the eye model was successfully performed over a 30° field of view. The measured virtual depth and the printed model papilla depth is linear correlated. The presented LF setup allowed high-quality 3D one-shot imaging and depth estimation of the optic nerve head in an eye model

An MINLP Model for designing decentralized energy supply network

In this report, a detailed description of an MINLP model for decentralized energy supply network optimization is given. This model includes the possibility of extending gas transmission lines, local choice of heating technology, as well as local decisions for energy-efficient house renovation. Ultimately, the model is aimed at finding cost-efficient network plans while reducing carbon emissions to a specified amount

Sheep in Wolf’s Clothing: The Role of Artifacts in Interpretive Schema Change

In this paper, we investigate the role of artifacts in a failed project that aimed at implementing a new culture of dealing with errors in a hospital by transferring safety standards from the aviation industry. We apply the interpretative method of objective hermeneutics to elucidate the role of artifacts as linking pins between diverging interpretive schemata and collective action during attempts to modify organizational routines. In particular, we show how the implementation of artifacts may serve as a means to satisfy a new espoused schema, while at the same time they are created and interpreted in ways that strengthen the old enacted schema. Although on the surface everyone would appreciate changes in treatment routines that help to avoid errors, the guiding norms of individual vigilance and self-centeredness, a culture that emphasizes hierarchy as a core value as well as the lack of sanctions for enacting the old schema led to a situation where the new espoused schema was never enacted. Instead, artifacts were used to stabilize a divergence between espoused and enacted schemata. Failure remained a cultural taboo.(VLID)342667

Assessment of Metal Hydride Reactors as Thermal Management Enhancement of Hydrogen Fuel Cells in Electric Aircraft

Electrified propulsion systems have the potential to reduce the environmental impact of aviation. Hydrogen fuel cells as primary energy supplier are a promising technology to power the electrically-driven propulsors. However, the thermal management of fuel cells is challenging due to their high amount of excess heat energy at a typically low temperature level. This work investigates the cooling potential of metal hydride (MH) reactors to enhance the thermal management system (TMS) of low temperature fuel cells. As a secondary function, the MH reactor can serve as an emergency hydrogen supply. There are two operation concepts of MH reactors considered in this study. In the first operation concept, the MH acts as a heat sink by absorbing some share of the heat of the fuel cell. This decreases the amount of heat to be removed by the TMS. In the second operation concept, the MH reactor operates as a heat pump to enlarge the temperature difference in the heat transfer fluid cycle. This improves the performance of the heat exchanger of the TMS to reject heat to the ambient air. For both operation modes, a sizing of an MH reactor and a heat exchanger is performed to estimate the impact on the TMS. While an exemplary general aviation aircraft serves as calculation example, the results are also applicable to commuter and regional aviation aircrafts. The study shows, that MH reactors have the potential to reduce the size of the heat exchanger significantly. In quasi-continuous heat pump operation, an MH reactor allows a reduction of the heat exchanger dimensions of up to 8 %. If the maximum heat rejection during take-off determines the heat exchanger size, a reduction of even 39% is reasonable when the MH reactor operates as a heat sink