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Hybrid manufacturing of titanium Ti-6Al-4V combining laser metal deposition and cryogenic milling
(2020)
Hybrid manufacturing, which, e.g., combines additive manufacturing with conventional machining processes, can be a way of overcoming limitations currently encountered in additive manufacturing. Cryogenic milling might be a viable option for hard-to-cut materials, as it leaves a contamination-free surface and can increase surface quality and tool life compared to conventional cooling concepts. In this study, the influence of cryogenic milling with carbon dioxide on titanium Ti-6Al-4V specimens manufactured with laser metal deposition (LMD) was investigated regarding tool wear and surface integrity in comparison to dry machining and machining with cooling lubricants. Moreover, additional layers of material were deposited on top of conventionally and cryogenically machined surfaces by means of LMD. The interface zone was then examined for defects. The milling process was closely monitored by means of thermal and high-speed imaging. Optical and tactile surface analysis provided evidence that lower roughness values and improved surface qualities could be obtained with cryogenic machining in comparison to dry machining. Moreover, significantly less tool wear was observed when a cryogenic cooling medium was applied. Although the utilization of conventional cooling lubricants resulted in satisfying surface qualities, substantial residual contamination on the milled surface was detected by means of fluorescence analysis. These contaminants are suspected to cause defects when the next layer of material is deposited. This is supported by the fact that pores were found in the weld bead applied on top of the milled specimens by means of LMD. Conversely, cryogenic machining resulted in very clean surfaces due to the residue-free evaporation of the coolant. Hence, a good metallurgical bonding between the weld bead and the milled substrate could be achieved. The results indicate the great potential of cryogenic milling in hybrid manufacturing, especially in terms of intermediate machining, as it provides residue-free surfaces for subsequent material deposition without an additional cleaning step and can significantly prolongate tool life.
Dissipation energy based parameter identification of anisotropic linear viscoelastic composites
(2020)
The current work presents a relaxation analysis based procedure to identify effective material parameters of the multiaxial generalized Maxwell model (GMM) by a numerical homogenization of the microscopic dissipation energy density for anisotropic linear viscoelastic composites. The employed GMM enables the derivation of a thermodynamically consistent constitutive law and a function of the dissipation energy density for direction‐dependent viscoelastic materials. The identity of this energy function to the microstructure's homogenized dissipation energy density is utilized for the identification of effective relaxation times. Furthermore, the identified relaxation times enable a simple determination of the remaining stiffness parameters. Finally, the presented procedure is demonstrated and evaluated for a randomly endless fibre‐reinforced plastic with a polymer matrix exhibiting a significant viscoelastic behaviour.
The purpose of this study is to examine the relationship between contextual work-related factors in terms of job demands (workload-WL) and job resources (work flexibility-WF), work-life conflict (WLC) and the burnout dimension emotional exhaustion (EE) in a large population-based sample. Building on the job demands resources model (JDRM), we have developed the hypothesis that WL has an indirect effect on EE that is mediated by WLC. We conducted a secondary analysis using data from the Dresden Burnout Study (DBS, N = 4246, mean age (SD) = 42.7 years (10.5); 36.4% male). Results from structural equation modelling revealed that EE is positively associated with WL (β = 0.15, p = 0.001) and negatively associated with WF (β = -0.13, p = 0.001), also after accounting for potential confounding variables (demography, depressive symptoms, and lifetime diagnosis of burnout). Both effects are mediated by WLC (β = 0.18; p = 0.001 and β = 0.08; p = 0.001, respectively) highlighting the important role of WLC in employee health. In summary, WF may help to reduce burnout symptoms in employees, whereas WL may increase them. Study results suggest that both associations depend on WLC levels.
Sieg/Maschmann, Unternehmensumstrukturierung – Arbeitsrecht, Datenschutz, Due Diligence, 3. Aufl.
(2022)
Standardfälle Arbeitsrecht
(2022)
Recht
(2022)
Die Seminararbeit untersucht die Bedeutung der strategischen Personalentwicklung und Kompetenzförderung im spezialisierten Bereich des Sondermaschinenbaus, mit einem Fokus auf die Praxis der Skill-Checks in einem deutschen Unternehmen. Sie beleuchtet die Auswirkungen des demografischen Wandels, der rasanten technologischen Entwicklungen und der Globalisierung auf den Bedarf an Fachkräften mit spezifischen technischen und sprachlichen Kompetenzen. Durch eine detaillierte Analyse der bestehenden Ausbildungs- und Weiterbildungsprozesse werden Schwachstellen aufgezeigt. Die Arbeit schlägt Lösungsansätze vor, wie durch strukturierte Weiterbildungsprogramme und verbesserte Auswahlverfahren diesen Herausforderungen effektiv begegnet werden kann, um die Wettbewerbsfähigkeit zu stärken.
The labor market is confronted with social, environmental, and economic developments that affect working conditions and individual labor relations. Lately, the Covid-19 pandemic has demonstrated and reinforced the importance of inclusive growth and sustainable work relationships. In this chapter, the smart job factory, a metamodel that supports the creation of new forms of work by redefining roles in labor, is introduced. The smart job factory is based on social entrepreneurship principles to drive innovative, sustainable, and long-term solutions to social challenges. For practical application, the model can be translated into a software solution that supports employers in the assessment of current working conditions and job roles within their companies and helps to redefine work relationships and to create new jobs. Thus, the smart job factory supports the labor market transition by systematically and proactively shaping new forms of work based on the triple bottom line of sustainable development.
Vitalpolitik
(2022)
Abstract: This chapter reconstructs the notion of ‘vital policy’ (Vitalpolitik), an approach to the social question whose first and strongest proponent amongst the Ordoliberals was Alexander Rüstow. It is opposed to traditional social policy as a top-down provision of material benefits (welfare). Instead, it aims at enabling those ‘conditions of life’ (Lebenslagen) that provide the prerequisites for human beings and their community to flourish. This humanistic approach attempts to complement the competitive processes in a market society and to provide access and equal opportunity to these processes, focusing on the notion of fair starting conditions for individuals. In its general thrust, Vitalpolitik is well compatible with more recent research programmes, especially the capability approach of Amartya Sen and Martha Nussbaum.
This paper embeds the early political economy of Friedrich August von Hayek in the intellectual milieu of German ordoliberalism. The urgency during the 1930s and 1940s to stabilize the disintegrating societal orders is identified as a crucial driver behind the parallelisms between Hayek and the ordoliberals. Their shared theoretical position is that in such moments, liberty can thrive sustainably only after a framework of general and stable rules has been established. Hayek’s proximity to ordoliberalism was most explicitly discernible in The Road to Serfdom and at the founding meeting of the Mont Pèlerin Society in 1947, culminating in the shared politico-economic vision of the competitive order. The contextual nature of Hayek’s ordoliberalism surfaced in the years after The Constitution of Liberty when his focus shifted, along with the postwar intellectual and institutional stabilization of the West: from how stable orders enable liberty, to how liberty enables the evolution of orders.
Stefan Kolev zeichnet in seinem Beitrag die Geschichte und Bedeutung des schillernden Begriffs »Neoliberalismus« nach, welcher vielfach als Grund allen Übels gegen liberales Denken und Politik in Stellung gebracht wird. Kolev plädiert dafür, dass der Liberalismus sich immer wieder erneuern muss, also stetig neue Neoliberalismen benötigt.
The intention of the paper is to consider the role of technologies used to overcome the COVID-19’s challenges in higher education. On investigating, it has been found that the digital strategies utilizing innovation technologies help students to adapt to pandemic consequences. This study enlightens the various technologies that assist systems of healthcare and education in diverse aspects to outlive against COVID-19. Furthermore, the technological shift of world economy that happened during the pandemic and its influence in the society is discussed. Besides the considered innovation technologies, this paper also deals with changes that have taken place in education system of Kazakhstan in pandemic circumstances. Alongside our suggested solution for further educational process issues is also presented.
A detailed review of the literature is done on COVID-19, digital technologies in education, blended learning using appropriate keywords on SCOPUS, Springer, Science Direct, and Google Scholar. To get insights some relevant sites and blogs are also taken into account. We have identified technologies used in Kazakhstan that play an important role now.
There have been chosen exploratory and conclusive research design. Fifty-nine students provided qualitative responses; ninety-eight students and graduates participated in quantitative survey. The results of study has shown students’ increased awareness concerning blended learning.
The scientific novelty lies in the description of the experience gained by higher schools during the quarantine. We believe that in the future, blended learning should be used largely. The innovations in the learning process cover two areas. The first is related to software used. It is like creation of a virtual university that facilitates communication between students and teachers. The second area correlates with content, without which any innovation will fail.
Abstract:
Background: Proctoring represents a cornerstone in the acquisition of state‐of‐the‐art cardiovascular interventions. Yet, travel restrictions and containment measures during the COVID‐19 pandemic limited on‐site proctoring for training and expert support in interventional cardiology.
Methods and Results: We established a teleproctoring setup for training in a novel patent foramen ovale closure device system (NobleStitch EL, HeartStitch Inc, Fountain Valley, CA) at our institution using web‐based real‐time bidirectional audiovisual communication. A total of 6 patients with prior paradoxical embolic stroke and a right‐to‐left shunt of grade 2 or 3 were treated under remote proctorship after 3 cases were performed successfully under on‐site proctorship. No major device/procedure‐related adverse events occurred, and none of the patients had a residual right‐to‐left shunt of grade 1 or higher after the procedure. Additionally, we sought to provide an overview of current evidence available for teleproctoring in interventional cardiology. Literature review was performed identifying 6 previous reports on teleproctoring for cardiovascular interventions, most of which were related to the current COVID‐19 pandemic. In all reports, teleproctoring was carried out in similar settings with comparable setups; no major adverse events were reported.
Conclusions: Teleproctoring may represent a feasible and safe tool for location‐independent and cost‐effective training in a novel patent foramen ovale closure device system. Future prospective trials comparing teleproctoring with traditional on‐site proctoring are warranted.
Hypotrochoidal profile contours have been produced in industrial applications in recent years using two-spindle processes, and they are considered effective high-quality solutions for form-fit shaft and hub connections. This study mainly concerns analytical approaches to determine the stresses and deformations in hypotrochoidal profile shafts due to pure bending loads. The formulation was developed according to bending principles using the mathematical theory of elasticity and conformal mappings. The loading was further used to investigate the rotating bending behaviour. The stress factors for the classical calculation of maximum bending stresses were also determined for all those profiles presented and compiled in the German standard DIN3689-1 for practical applications. The results were also compared with the corresponding numerical and experimental results, and very good agreement was observed. Additionally, based on previous work, the stress factor was determined for the case of torsional loading to calculate the maximum torsional stresses in the standardised profiles, and the results are listed in a table. This study contributes to the further refinement of the current DIN3689 standard.
Abstract: Duplex steels are used for applications that require high strength and ductility combined with good corrosion resistance. An economical welding technology to handle these steels is achieved by combining the MIG and TIG arc processes. The aim is to improve welding speed and quality by utilizing a TIG-MIG hybrid welding process to join 1.4462 duplex steel with a thickness of 2 mm. The interaction between the two arcs, caused by the blowing effect, is an enormous challenge that can be counteracted with a defined torch position and current modulation. For this purpose, a variation of the MIG (pulsed and AC pulsed arc) and TIG process (AC and pulsed DC) took place. The influence of electrical parameters on process stability and material transfer was investigated. For analysis, an evaluation of high-speed recordings (5000 frames per second) and synchronized measured current/voltage curves (200 kHz) is carried out. Based on a number of selected specimens, a welding procedure test according to ISO 15614-1 is performed to determine the welding seam quality. The test includes the characterization by tensile and hardness testing and macroscopic and microscopic examination. Additionally, the specimens are examined according to ISO 5817.