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Renewable Energy Integration for Steam Supply of Industrial Processes—A Food Processing Case Study
(2020-05-16)
This study highlights the CO2,e -emission reduction potentials and related economic consequences for changing steam generation from fossil to renewable. Seven different utility concepts are developed, including a steam accumulator for load management. Peculiarities for the integration of biogas boilers, biomass-fuelled boilers, electrode steam boilers, biomethane-fuelled solid oxide fuel cells, micro gas turbine, solar energy systems, heat pumps and steam accumulators into a steam system with fluctuating steam demand ...
Aufsatz
Probabilistic upscaling and aggregation of wind power forecasts
(2020-03-16)
Background
Wind power forecasts of the expected wind feed-in for the next hours or days are necessary to integrate the generated volatile wind energy into power systems. Most forecasting models predict in some sense the best value, but they ignore the other possible outcomes which may arise because of forecasting uncertainties. Probabilistic forecasts, on the other hand, also predict a distribution of possible outcomes with their respective probabilities that specific power values will occur and therefore have higher ...
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Review of Steady-State Electric Power Distribution System Datasets
(2020-09-15)
Publicly available grid datasets with electric steady-state equivalent circuit models are crucial for the development and comparison of a variety of power system simulation tools and algorithms. Such algorithms are essential to analyze and improve the integration of distributed energy resources (DERs) in electrical power systems. Increased penetration of DERs, new technologies, and changing regulatory frameworks require the continuous development of the grid infrastructure. As a result, the number and versatility of ...
Aufsatz
Effect of Compositional Variation Induced by EBM Processing on Deformation Behavior and Phase Stability of Austenitic Cr-Mn-Ni TRIP Steel
(2020-01-24)
Electron beam melting (EBM) is an established powder bed-based additive manufacturing process for the fabrication of complex-shaped metallic components. For metastable austenitic Cr-Mn-Ni TRIP steel, the formation of a homogeneous fine-grained microstructure and outstanding damage tolerance have been reported. However, depending on the process parameters, a certain fraction of Mn evaporates. This can have a significant impact on deformation mechanisms as well as kinetics, as was previously shown for as-cast material. ...
Aufsatz
SimBench—A Benchmark Dataset of Electric Power Systems to Compare Innovative Solutions Based on Power Flow Analysis
(2020-06-26)
Publicly accessible, elaborated grid datasets, i.e., benchmark grids, are well suited to publish and compare methods or study results. Similarly, developing innovative tools and algorithms in the fields of grid planning and grid operation is based on grid datasets. Therefore, a general methodology to generate benchmark datasets and its voltage level dependent implementation is described in this paper. As a result, SimBench, a comprehensive dataset for the low, medium, high and extra-high voltage level, is presented. ...
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Experimentelle Untersuchung zur Mehrphasenströmung in öleingespritzten Mehrphasenschraubenspindelpumpen
(2020-02-18)
Für die Förderung von Gemischen mit hohen Gasanteilen erfolgt die Entwicklung eines neuen Kühlkonzepts, indem das Prozessfluid in flüssiger Phase extern in die Förderkammer einer Mehrphasenpumpe eingespritzt wird. Neben der Regulierung des Thermomanagements trägt dies zur Spaltabdichtung bei, so dass der effektiv geförderte Volumenstrom steigt. Zur Untersuchung der Thermo‐ und Fluiddynamik einer solchen Mehrphasenpumpe wird ein transparentes Förderkammermodell der Pumpe mit externer Fluideinspritzung entwickelt. Das ...
Aufsatz
On the Impact of Texture and Grain Size on the Pseudoelastic Properties of Polycrystalline Fe–Ni–Co–Al–Ti Alloy
(2020-05-08)
The effects of thermomechanical treatments on crystallographic texture and grain size evolution and their impact on the pseudoelastic properties in Fe41–Ni28–Co17–Al11.5–Ti2.5 (at.%) were studied in the present paper. The results show that cold rolling leads to brass-type texture in this alloy, which is typical for low stacking fault energy materials. Thermal treatments up to 1300 °C were conducted and it is shown that the presence of β-phase helps to control grain growth. After the dissolution of the secondary phase ...
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Rechtsverträgliche und qualitätszentrierte Gestaltung für "KI made in Germany"
(2020-02-21)
Künstlich intelligente (KI) Systeme erfreuen sich immer größerer Beliebtheit. Insbesondere smarte persönliche Assistenten (SPAs) von Amazon, Google und vielen weiteren verzeichnen ein stetiges Marktwachstum. Den vielfältigen Potenzialen dieser KI-Systeme stehen jedoch auch zahlreiche Risiken gegenüber. Berichte von Datenpannen und -lecks häufen sich und haben bei Nutzern eine zunehmende Skepsis zur Folge, was zu einem gespaltenen Bild von KI in der Gesellschaft beiträgt. Diesem Problem stellt sich das Forschungsprojekt ...
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Improving Vertical Wind Speed Extrapolation Using Short-Term Lidar Measurements
(2020-03-29)
This study investigates how short-term lidar measurements can be used in combination with a mast measurement to improve vertical extrapolation of wind speed. Several methods are developed and analyzed for their performance in estimating the mean wind speed, the wind speed distribution, and the energy yield of an idealized wind turbine at the target height of the extrapolation. These methods range from directly using the wind shear of the short-term measurement to a classification approach based on commonly available ...
Aufsatz
Comparison between Hyperspectral Imaging and Chemical Analysis of Polyphenol Oxidase Activity on Fresh-Cut Apple Slices
(2020-06-29)
The assessment of the quality of fresh-cut apple slices is important for processing, storage, market value, and consumption. Determination of polyphenol oxidase activity (PPO) in apples is critical for controlling the quality of the final product (i.e., dried apples and juices). Hyperspectral imaging (HSI) is a nondestructive, noncontact, and rapid food quality assessment technique. It has the potential to detect physical and chemical quality attributes of foods such as PPO of apple. The aim of this study was to ...