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Comparison of Real and Simulated Fiber Orientations in Injection Molded Short Glass Fiber Reinforced Polyamide by X-ray Microtomography
(2021-12-22)
During injection molding of short glass fiber reinforced composites, a complex structure is formed due to the fiber movement. The resulting fiber orientation can be predicted using various simulation models. However, the models are known to have inadequacies andthe influence of process and model parameters is not clearly and comprehensively described. In this study, the aforementioned model and process parameters are investigated to determine the dependencies of the individual influences on the real and simulated ...
Aufsatz
A Novel Approach to Inhibit Intergranular Corrosion in Ferritic Stainless Steel Welds Using High-Speed Laser Cladding
(2021-12-15)
Ferritic stainless steels are prone to localized corrosion phenomena such as pitting corrosion or intergranular corrosion, in particular when jointed by fusion welding processes. State-of-the-art techniques to avoid intergranular corrosion mainly consist of alternating alloy concepts or post-weld heat-treatments—all of which are associated with increased production costs. Hence, the present investigation seeks to introduce a novel approach for the inhibition of intergranular corrosion in ferritic stainless steel welds ...
Aufsatz
Heat Load Profiles in Industry and the Tertiary Sector: Correlation with Electricity Consumption and Ex Post Modeling
(2022-03-29)
The accurate prediction of heat load profiles with a daily resolution is required for a broad range of applications, such as potential studies, design, or predictive operation of heating systems. If the heat demand of a consumer mainly originates from (production) processes independent of the ambient temperature, existing load profile prediction methods fail. To close this gap, this study develops two ex post machine learning models for the prediction of the heat demand with a daily resolution. The selected input ...
Aufsatz
Efficiency and agility of a liquid CO2 cooling system for molten metal systems
(2021-09-24)
In this study investigations on the efficiency and agility of a liquid CO2 cooling system, using expansion bores fed with liquid CO2 by capillary tubes, to form a thermal seal in a magnesium hot runner channel are performed in a test rig. Via temperature measurements the performance of different sets of cooling parameters is tested and cooling rates are identified depended on a varying nozzle geometry. To validate the measurements, the tests are modelled in a thermal simulation study. The applicability of the liquid ...
Aufsatz
Performance of field-scale lab vs in situ visible/near- and mid-infrared spectroscopy for estimation of soil properties
(2021-10-10)
Comparison of laboratory versus in situ visible/near- (visNIR) and mid-infrared (MIR) spectroscopy for prediction of various soil properties is required to demonstrate trade-offs between accuracy and efficiency. Field measurements were made on an arable field in Germany (silt loam Haplic Luvisol) using visNIR (ASD FieldSpec 3 Hi-Res) and MIR (Agilent Technologies 4300 Handheld FTIR) and material was collected for lab visNIR (Foss XDS Rapid Content Analyzer) and MIR (Bruker-TENSOR 27) measurements on dried and ground ...
Aufsatz
High optical gain in InP-based quantum-dot material monolithically grown on silicon emitting at telecom wavelengths
(2022-04-01)
We describe the fabrication process and properties of an InP based quantum dot (QD) laser structure grown on a 5° off-cut silicon substrate. Several layers of QD-based dislocation filters embedded in GaAs and InP were used to minimize the defect density in the QD active region which comprised eight emitting dot layers. The structure was analyzed using high resolution transmission electron microscopy, atomic force microscopy and photoluminescence. The epitaxial stack was used to fabricate optical amplifiers which ...
Aufsatz
3DWoodWind: robotic winding processes for material-efficient lightweight veneer components
(2022-03-25)
Winding processes are known from fiber composite technology for highly resistance lightweight components for aviation. These fiber-based processes work predominantly with synthetic composites made of carbon or glass fibers. For the construction industry, these additive processes are very promising and resource-efficient building processes, but they are still hardly used in timber construction despite the very high level of digitalization and technical development. The 3DWoodWind research project uses a continuous ...
Aufsatz
Design based on availability: Generative design and robotic fabrication workflow for non-standardized sheet metal with variable properties
(2022-03-07)
This paper presents the use of a computational design algorithm in combination with robotic fabrication and sensing to augment the design and construction process for non-standardized material. Although reusing reclaimed material can significantly reduce the environmental impact in building construction, current design processes are not set up for this shift in thinking. Contrary to conventional practices, designing within the constraints of available material means that geometry and topology cannot be fully ...
Aufsatz
Virtual Reality Experience of Mega Sports Events: A Technology Acceptance Study
(2022-05-24)
Digitalization has advanced to become an opportunity to spectate sports during the pandemic and its restrictions for traveling to competitions. The purpose of this study is to investigate the antecedents of using virtual reality technology for spectating mega sports events. Based on a literature review, the authors created a model of behavioral intention, built on the unified theory of acceptance and use of technology and technology acceptance model to examine the curiosity and self-construal of spectators. An online ...
Aufsatz
Enhancement of Weldability at Laser Beam Welding of 22MnB5 by an Entrained Ultrasonic Wave Superposition
(2022-07-09)
In this paper, the potential of directional ultrasonic wave superposition by moving sound generators for laser beam welding of high-strength steel alloys 1.5528 (22MnB5) is studied. Steel sheets of identical thickness and in form of tailored blanks were joined in butt joint configuration. The influences of the various excitation parameters of the moving sound generators on the ultrasonic coupling and their influence on the distribution of the AlSi coating components within the melting zone and the weld seam characteristics ...