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Buch
Abschlussergebnisbericht - KMU-Wissenstransferlabor „Digitale Fabrik“
(2023-04)
Der digitale Wandel stellt aufgrund der hohen Gestaltungskomplexität insbesondere kleine und mittlere Unternehmen (KMU) immer noch vor große Herausforderungen. Reifegradmodelle und Roadmaps bieten Möglichkeiten, diese Komplexität beherrschbar zu machen. Vor diesem Hintergrund hat das Fachgebiet Produktionsorganisation und Fabrikplanung an der Universität Kassel im Rahmen des Forschungsprojektes Wissenstransferlabor „Digitale Fabrik“ (Wislab) ein KMU-spezifisches Reifegradmodell, einen zugehörigen Erhebungsleitfaden ...
Dissertation
Modellierung von offenen Absorptionsanlagen zur Raum- und Prozessluftentfeuchtung
(2023)
Luftentfeuchtung erfolgt in herkömmlichen Trocknungs- und Klimatisierungsanlagen durch eine Kühlung der feuchten Luft unter ihren Taupunkt (Kondensationsentfeuchter) und einer anschließenden Erwärmung bis zu der gewünschten Temperatur. Das Prinzip dieser Betriebsweise birgt einen unnötigen Stromverbrauch. In der vorliegenden Dissertation wird daher ein alternatives Luftentfeuchtungsverfahren beschrieben, bei dem die Luftentfeuchtung durch einen offenen Absorptionsprozess realisiert wird. In dem offenen Absorptionsprozess ...
Dissertation
Practical application of active premagnetization in transformerless DC/DC converters
(2023-05-17)
Magnetic devices are used in almost every power electronic system. Therefore, their purpose and with that their requirements can vary in a wide range. The consequence is a large number of options regarding the priority of optimisation. In this work, the focus is on reducing the volume or weight of inductors in transformerless DC-DC converters. Active prmeagnetization is choosed as an optimisation approach. The technique enables an operation of the DC-DC-converter in the Triangular Current Mode (TCM), whereby ...
Dissertation
Characterisation of Cold Asphalt Mixtures with the Addition of Active Fillers
(2023)
Climate change, the limited availability of natural resources, and energy crises are putting pressure on the global societies? to employ low-energy and low-emission technologies for road pavement construction. Cold Recycled Materials (CRM) is an efficient and low-impact solution. CRM with Bituminous Emulsion (CRM-BE) is one of the most common types of CRM. CRM-BEs are created at ambient temperature by combining a high amount of Reclaimed Asphalt (RA) with Bitumen Emulsion (BE). BE used in CRM is typically composed ...
Dissertation
Numerical simulation of a sub-wavelength plasmonic THz antenna for bio-sensing applications
(2023)
In the past decades, bio-sensing has become a steadily growing field in the life-sciences. Popular subjects of investigation are proteins, which for instance mediate intra-cellular transfer of substances and thus are attractive drug targets. They are also responsible for the occurence of degenerative diseases such as Alzheimer’s disease and the Creutzfeld-Jakob disease. Examining proteins to uncover their fundamental properties and behavior is important in order to advance modern health care and medicine. One way to ...
Dissertation
Plastic packaging waste management in Germany: Evaluating and optimizing material flows and environmental impacts
(2023)
Since 1990, the annual plastic packaging consumption by private end users in Germany more than doubled. This trend can be attributed to plastic's advantageous properties such as its low weight, cost-effectiveness, and customizable features. However, plastic packaging is also widely criticized due to its dependency on fossil fuels, short lifespan, and potential contribution to marine littering. The tension between the popularity of plastic packaging and the environ-mental challenges associated with a short-term product ...
Aufsatz
Experimental Analysis of Residual Stresses in CFRPs through Hole-Drilling Method: The Role of Stacking Sequence, Thickness, and Defects
(2023-05-09)
Carbon fiber reinforced plastics (CFRPs) gained high interest in industrial applications because of their excellent strength and low specific weight. The stacking sequence of the unidirectional plies forming a CFRP laminate, and their thicknesses, primarily determine the mechanical performance. However, during manufacturing, defects, e.g., pores and residual stresses, are induced, both affecting the mechanical properties. The objective of the present work is to accurately measure residual stresses in CFRPs as well ...
Aufsatz
Describing mechanical damage evolution through in situ electrical resistance measurements
(2023-02-27)
The fatigue properties of metallizations used as electrical conductors in flexible electronic devices have been thoroughly studied over the years. Most studies use time-intensive characterization methods to evaluate mechanical damage. For their ease of access, in situ electrical resistance measurements are often performed along with other characterization methods. However, the data are mostly used as an indicator of failure and a thorough analysis is usually missing. This work presents some deeper analysis methods ...
Aufsatz
Elevated Temperature Mechanical Characteristics and Fracture Behavior of a Novel Beta Titanium Alloy
(2023-02-03)
In the present work, the elevated-temperature deformation characteristics and microstructural evolution of a Ti-5V-5Mo-5Cr-4Al alloy in solution-treatment conditions were studied under a tensile load at temperatures in the range of 25 to 550 °C and strain rates between 0.001 and 0.1 s-¹. The results obtained indicated that, essentially, dynamic recovery (DRV) was the dominant softening mechanism in the case of the regimes considered. An analysis based on transmission electron microscopy (TEM) and the assessment of ...
Dissertation
Lignocellulosic biorefinery with a thermo-biological pretreatment concept
(2023)
There is great interest, not only in technologically advanced societies, in developing innovative sources of raw materials, especially lignocellulosic biomasses such as cereal straw, which do not interfere with food production. In Germany, 4 – 9 million tons of cereal straw, mainly wheat, are utilized annually, corresponding to an energy potential of 57 – 129 PJ/a. Lignocellulose, found in plant cell walls, consists of hemicellulose, cellulose, and lignin, and it requires complex fractionation to enable its polymers ...