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Aufsatz
Effect of Friction Stir Processing on Microstructural, Mechanical, and Corrosion Properties of Al-Si12 Additive Manufactured Components
(2020-01-03)
Additive manufacturing (AM) is an advanced manufacturing process that provides the opportunity to build geometrically complex and highly individualized lightweight structures. Despite its many advantages, additively manufactured components suffer from poor surface quality. To
locally improve the surface quality and homogenize the microstructure, friction stir processing (FSP) technique was applied on Al-Si12 components produced by selective laser melting (SLM) using two different working media. The effect of FSP on ...
Aufsatz
Influence of complex geometries on the properties of laser-hardened surfaces
(2020-04-25)
Laser surface hardening provides for many advantages in terms of flexible production due to very localized and controlled energy input into the material. Laser processing offers the possibility to treat surfaces in order to locally strengthen the areas that are prone to fatigue cracking. It is well known that laser energy absorption depends on many parameters, e.g., the surface structure and the surface orientation. The incident angle of the laser beam plays a key role in this regard. When complex geometries like ...
Aufsatz
Absolute Kr 4s-electron photoionization cross sections between 30 and 90 eV measured by photon-induced fluorescence spectroscopy (PIFS)
(1994)
Absolute Kr 4s-electron photoionization cross sections as a function of the exciting-photon energy between 30 and 90 eV were measured by photon-induced fluorescence spectroscopy (PIFS). The measurements were compared with available experimental data and theoretical calculations.
Aufsatz
Threshold scan of the Ne 2s-electron photoionization cross edition
(1990)
The photoionization of the Ne 2s-electrons was studied from threshold to 1 eV above threshold. The technique of photon-induced fluorescence spectroscopy was applied. Pronounced structures were observed resulting from autoionization of doubly excited atomic states. A threshold cross section of 0.17 Mb was determined.
Aufsatz
Interchannel interactions and relaxation in the 2p auger spectra of Mg-like ions
(1992)
Relativistic Auger rates for the 2p spectra of Mg-like ions have been calculated in the atomic range 13 < Z < 36. We used the multiconfiguration Dirac-Fock method but beyond a simple frozen-orbital approach we include also relaxation for the bound electrons and the interchannel interaction between the continuum states. Both effects may alter the individual transition rates remarkably. This is analysed for a few selected states within the isoelectronic sequence. Weak transitions within the 2p spectra can be changed ...
Aufsatz
Calculation of the hyperfine structure transition energy and lifetime in the one-electron Bi^82+ ion
(1993)
We calculate the energy and lifetime of the ground state hyperfine structure transition in one-electron Bi^82+ . The influence of various distributions of the magnetic moment and the electric charge in the nucleus ^209_83 Bi on energy and lifetime is studied.
Aufsatz
Agricultural, architectural and archaeological evidence for the role and ecological adaptation of a scattered mountain oasis in Oman
(2005)
The recent discovery of the monumental 5000 years old tower tombs on top of the up to 1850 m high Shir plateau has raised numerous questions about the economic and infrastructural basis of the agro-pastoral-piscicultural society which likely has constructed them. The scattered oasis settlement of Maqta, situated just below the towers in a rugged desert environment has therefore been studied from 2001 to 2003 to understand its prehistoric and present role along the ancient trade route which connected the inner-Omani ...
Aufsatz
Formen der Öffnung im Fremdsprachenunterricht: ein Gedankenaustausch
(1998)
Formen der . Öffnung" - was ist damit eigentlich gemeint? Woher kommt das Interesse an diesem Thema? Was spricht für Öffnung, was spricht dagegen? Welche Vorteile darf man von Öffnung erwarten, welche neuen Probleme gilt es zu lösen? Und welche Konsequenzen ergeben sich, wenn man erst einmal mit Öffnung beginnt? Für uns besteht eine Konsequenz darin, nicht nur das Konzept von Unterricht, sondern auch das Sprechen darüber zu verändern. Und so haben wir zwei engagierten Kolleginnen, Frau Ferrante und Frau Rosendahl-Schnelle, ...
Aufsatz
Report for Politicians
(2017)
Purpose – This paper provides a comprehensive overview of the understanding of politicians about social entrepreneurship and its ecosystem. These findings are contrasted with the needs and wishes of social entrepreneurs. Design/methodology/approach – The research used a qualitative research approach. We conducted in-depths interviews with entrepreneurs, politicians, and high-level responsible administrators responsible persons of eight European countries. Data analysis covers pattern matching and case comparison. ...
Aufsatz
Report for Chambers of Commerce and Start-up Centres
(2017-08-18)
Purpose – This report provides a comprehensive overview of the needs and wishes of entrepreneurs and contrasts them with the spectrum of services and support offered by start-up centres and chambers of commerce who participated in this study. Design/methodology/approach – The paper uses a qualitative research approach. In total, we conducted 57 in-depths interviews with entrepreneurs, start-up centres and the chambers of commerce of eight European countries. Data analysis covers pattern matching and case comparison. ...