Der Techniker - Austrocknung und Wiederbelebungsversuche in der DDR, problematische Neu-Etablierung in der Marktwirtschaft

Die Verfasser stellen zunächst die Erosion des Technikerberufs im Bildungs- und Beschäftigungssystem der DDR in den sechziger Jahren dar. Die setzen sich im folgenden mit der Wiedereinführung dieses Bildungsganges im Zuge der Reform der Ingenieurausbildung in den achtziger Jahren auseinander und skizzieren die neue Gestaltung der Technikerausbildung sowie den Widerstand gegen diese Reform. Mit der Einführung der Marktwirtschaft westdeutscher Prägung waren in den neunziger Jahren in den neuen Bundesländern im Prinzip gute Bedingungen für die Stabilisierung des Technikerberufs gegeben, die sich jedoch aufgrund blockierender Faktoren des Transformationsprozesses selbst sowie aufgrund von Hypotheken der Vergangenheit nicht durchsetzen konnten. Die Verfasser ziehen insgesamt ein skeptisches Resümee der Zukunftsperspektiven des Technikerberufs. (ICE

Probleme der dialektischen Beziehungen von Arbeiterklasse und wissenschaftlich-technischer Intelligenz - ein Beitrag zur Erforschung der sozialen Annaeherung dargestellt anhand einer Sekundaeranalyse von Materialien empirischer soziologischer Untersuchungen aus den Jahren 1970-1978

SIGLEDB Leipzig(101) - Di 1983 B VD 163, T. 1, 2 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Investigation of multilayer coating of EN AW 6060 – T66 using friction surfacing

The objective of this research is to investigate observable process changes during multi-layer friction surfacing of EN AW 6060 aluminum, whether for repair, remanufacturing, or new part manufacturing. In this study, friction surfacing was performed with a 10-mm-diameter rod of EN AW 6060 aluminum at spindle speeds ranging from 1000 to 7000 rpm to create up to three layers of 40-mm-long deposits on a substrate of the same alloy. The process forces and layer temperatures were observed. Post-process measurement of flash geometry, layer geometry and microhardness were conducted with the motivation to understand the impact of multi-layer depositions on performance and identifying acceptable conditions required to achieve acceptable build quality. The thickness, deposition and joining efficiency of layers in the multilayer configuration remained consistent. Friction surfacing of EN AW 6060 aluminum allowed for high deposition rates of 9 kg/hr, when compared to other metal additive technologies

Free volume in ionic liquids: a connection of experimentally accessible observables from PALS and PVT experiments with the molecular structure from XRD data

In the current work, free volume concepts, primarily applied to glass formers in the literature, were transferred to ionic liquids (ILs). A series of 1-butyl-3-methylimidazolium ([C4MIM](+)) based ILs was investigated by Positron Annihilation Lifetime Spectroscopy (PALS). The phase transition and dynamic properties of the ILs [C4MIM][X] with [X](-) = [Cl](-), [BF4](-), [PF6](-), [OTf](-), [NTf2](-) and [B(hfip)(4)](-) were reported recently (Yu et al., Phys. Chem. Chem. Phys., 2012, 14, 6856-6868). In this subsequent work, attention was paid to the connection of the free volume from PALS (here the mean hole volume, ) with the molecular structure, represented by volumes derived from X-ray diffraction (XRD) data. These were the scaled molecular volume V-m,V-scaled and the van der Waals volume V-vdw. Linear correlations of at the "knee'' temperature ((T-k)) with V-m,V-scaled and V-vdw gave good results for the [C4MIM](+) series. Further relationships between volumes from XRD data with the occupied volume V-occ determined from PALS/PVT (Pressure Volume Temperature) measurements and from Sanchez-Lacombe Equation of State (SL-EOS) fits were elaborated (V-occ(SL-EOS) approximate to 1.63 V-vdw, R-2 = 0.981 and V-occ(SL-EOS) approximate to 1.12 V-m,V-scaled, R-2 = 0.980). Finally, the usability of V-m,V-scaled was justified in terms of the Cohen-Turnbull (CT) free volume theory. Empirical CT type plots of viscosity and electrical conductivity showed a systematic increase in the critical free volume with molecular size. Such correlations allow descriptions of IL properties with the easily accessible quantity V-m,V-scaled within the context of the free volume