Publikationsserver der Westfälischen Hochschule
Not a member yet
2819 research outputs found
Sort by
Inflation und Geldpolitik im Euroraum - eine kritische Analyse
No full textDie Ukrainekrise und coronabedingte Lieferkettenprobleme treiben derzeitdie Rohstoff-, Material- und Lebensmittelpreise hoch. Auch die Inflationser-wartungen steigen; es drohen Zweitrundeneffekte imGefolge höhererLohnforderungen und Lohnabschlüsse. Langfristig könnten in der Eurozoneweitere Faktoren die Inflation treiben, z.B. angebotsseitig der Fachkräfte-mangel sowie globale Nahrungsmittelknappheiten und politikseitig diegewollten Effekte der Klimapolitik. Der Beitrag diskutiert vor diesemHinter-grund geldpolitische Implikationen
Kosten- und Umsatzsynergien als Akquisitionsmotiv - eine Bestandsaufnahme
No full textEin größerer Anteil der in den letzten Jahren vorgenommenen Unternehmensakquisitionen wurde maßgeblich mit attraktiven Synergieerwartungen begründet. Bei näherer Betrachtung können diese Synergien oft nur wenig präzise quantifiziert und der Zeitpunkt ihrer Realisierung nur ungenau eingeordnet werden. Der vorliegende Beitrag zeigt die Bedeutung von Synergien in Verbindung mit dem Goodwill, grenzt die Kosten- und Umsatzsynergien inhaltlich ab und befasst sich auf der Basis zahlreicher Studien mit dem aktuellen Erkenntnisstand in Verbindung mit der Vorbereitung und Realisierung von Kosten- und Umsatzsynergien
Hot-Corrosion and Particle Erosion Resistance of Co-Based Brazed Alloy Coatings
No full textTape brazing constitutes a cost-effective alternative surface protection technology for complex-shaped surfaces. The study explores the characteristics of high-temperature brazed coatings using a cobalt-based powder deposited on a stainless-steel substrate in order to protect parts subjected to hot temperatures in a wear-exposed environment. Microstructural imaging corroborated with x-ray diffraction analysis showed a complex phased structure consisting of intermetallic Cr-Ni, C-Co-W Laves type, and chromium carbide phases. The surface properties of the coatings, targeting hot corrosion behavior, erosion, wear resistance, and microhardness, were evaluated. The high-temperature corrosion test was performed for 100 h at 750 � C in a salt mixture consisting of 25 wt.% NaCl + 75 wt.% Na2SO4. The degree of corrosion attack was closely connected with the exposure temperature, and the degradation of the material corresponding to the mechanisms of low-temperature hot corrosion. The erosion tests were carried out using alumina particles at a 90� impingement angle. The results, correlated with the microhardness measurements, have shown that Co-based coatings exhibited approximately 40% lower material loss compared to that of the steel substrate
Impact of cobalt content and grain growth inhibitors in laser-based powder bed fusion of WC-Co
No full textProcessing of tungsten carbide‑cobalt (WC-Co) by laser-based powder bed fusion (PBF-LB) can result in characteristic microstructure defects such as cracks, pores, undesired phases and tungsten carbide (WC) grain growth, due to the heterogeneous energy input and the high thermal gradients. Besides the processing conditions, the material properties are affected by the initial powder characteristics. In this paper, the impact of powder composition on microstructure, phase formation and mechanical properties in PBF-LB of WC-Co is studied.
Powders with different cobalt contents from 12 wt.-% to 25 wt.-% are tested under variation of the laser parameters.
Furthermore, the impact of vanadium carbide (VC) and chromium (Cr) additives is investigated. Both are known as grain growth inhibitors for conventional sintering processes. The experiments are conducted at a pre-heating temperature of around 800 ◦C to prevent crack formation in the samples. Increasing laser energy input reduces porosity but leads to severe embrittlement for low cobalt content and to abnormal WC grain growth for high cobalt content. It is found that interparticular porosity at low laser energy is more severe for low cobalt content due to poor wetting of the liquid phase. Maximum bending strength of σB > 1200 MPa and Vickers hardness of approx. 1000 HV3 can be measured for samples generated from WC-Co 83/17 powder with medium laser energy input. The addition of V and Cr leads to increased formation of additional phases such as Co3W3C, Co3V and Cr23C6 and to increased lateral and multi-laminar growth of the WC grains. In contrast to conventional sintering, a grain growth inhibiting effect of V and Cr in the laser molten microstructure is not achieved
Impact of COVID-19 Pandemic on the Educational-Instructional Process of the Students from Technical Faculties
No full textEven though we live in a period when the word digitization is prevalent in many social areas, the COVID-19 pandemic has divided mankind into two main categories: some people have seen this crisis as an opportunity to move the activities online and, furthermore, to accelerate digitization in as many areas as possible, while others have been reluctant, keeping their preferences for face-to-face activities. The current work presents the results of an analysis on 249 students from 11 engineering faculties. The study aims to identify the impact of the COVID-19 pandemic on students’ educational experiences when switching from face-to-face to online education during a public health emergency or COVID 19-related state of alert. The overall conclusion was that, although the pandemic has brought adverse consequences on the health and life quality of many people, the challenges that humankind has been subjected to have led to personal and professional development and have opened up new perspectives for carrying out the everyday activities
Carolin, Göthe, a traveling salesman and the art of computer science
No full textAt the beginning of the pandemic in Feb. 2020 I had a little time and wanted to do something new i.e. bring my 3D printer, AI and computer science together somehow. The result is a printed portrait with a lot of computer science. Using style transfer I transferred the etching style of a Göthe portrait to a young girl I call Carolin. By means of image processing I made a black and white picture out of it. Then, using the problem of the traveling salesman, each black point in the picture is interpreted as a city and the whole picture is drawn by only one line. Since this line is very long, it is optimized and shortened by a so-called simulated annealing algorithm. The result is printed in 5 layers on a 3D printer
Small commercial UAVs for indoor Search and Rescue Missions
No full textThis technical report is about the architecture and integration of very small commercial UAVs (< 40 cm diagonal) in indoor Search and Rescue missions. One UAV is manually controlled by only one single human operator delivering live video streams and image series for later 3D scene modelling and inspection. In order to assist the operator who has to simultaneously observe the environment and navigate through it we use multiple deep neural networks to provide guided autonomy, automatic object detection and classification and local 3D scene modelling. Our methods help to reduce the cognitive load of the operator. We describe a framework for quick integration of new methods from the field of Deep Learning, enabling for rapid evaluation in real scenarios, including the interaction of methods
Distributed intercultural project-based learning - A novel approach - Experiences from a quadrilateral interdisciplinary collaboration
No full textThis paper describes a new concept and experiences of a distributed interdisciplinary learning programme for students across continents. The aim is to provide students with a truly Global Intercultural Project Experience (GIPE) by working together with peers from around the world, and solving real-life client’s problems. We have received seed-funding for four annual projects to engage students from Germany (Europe), Namibia (Africa), Indonesia (Asia), and Peru (Latin-America). In 2020, 30 students from four continents engaged in a one-semester distributed software development project for a Namibian client. Despite Covid-19 they successfully completed the project expressing deep appreciation for the learning opportunities overcoming challenges of working across wide-spread time zones, cultures, changing requirements, and various technical challenges. Considering the vast learning benefits, we suggest to incorporate such projects in all tertiary education curricula across the globe
Die Arbeitszeit des Betriebsrats – rechtliche Einordnung und Empfehlungen zur Gestaltungspraxis
Get PDFDer Aufsatz behandelt die rechtliche Frage, wie die Tätigkeit des Betriebsrates als Arbeitszeit i. S. d. Arbeitszeitgesetzes einzuordnen ist
