Search

In order to reduce CO2 emission and energy consumption, more recycled secondary materials have to be used in foundry industry, especially for Al-Si-Mg based alloys for semi-solid processing. In this paper, Al-Si-Mg based alloys with the addition of recycled secondary materials up to 30 % (10, 20, 30 %, respectively) have been produced by semi-solid processing. The solidification microstructure was investigated using optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Furthermore, computed tomography (CT) was also used to elucidate the size, size distribution, number density, volume fraction of porosities. It was found that with the addition of the recycled secondary materials up to 30 %, there is no significant effect on the solidification microstructure in terms of the grain size and the shape factor of primary α-Al and the second α-Al. More importantly, the morphology of eutectic Si can be well modified and that of the Fe-containing phase (π-AlSiMgFe) can be tailored. Furthermore, with increasing recycled secondary materials, at least another two important issues should also be highlighted. Firstly, more TiB2 particles were observed, which can be due to the addition of Al-Ti-B grain refiners for the grain refinement of recycled secondary materials. Secondly, a significant interaction between Sr and P was also observed in the recycled secondary materials. The present investigation clearly demonstrates that Al-Si-Mg based alloys with the addition of recycled secondary materials at least up to 30% can be used for semi-solid processing, which may facilitate better sustainability.

In a multilateral ecumenical setting, this paper analyses the challenges Christian churches have to deal with in modern »secularized« societies. First, it outlines Charles Taylor’s study The Secular Age as a helpful tool to understand the fundamental cultural changes. Second, it highlights three characteristic shifts: the continuous decrease of membership in mainline churches, the growing diversity of (Christian and non-Christian) religious communities, and the failing transgenerational transmission of religious knowledge and practice. As churches cannot any longer take their cultural relevance for granted, third, the paper pleas for an attitude of ›exploring relevance‹ which is open to new forms of communicating the gospel without, however, losing confidence in the respective formative traditions. Finally, the paper argues that, because all churches share these challenges, the situation encourages ecumenism.

Blast-induced fines in rock negatively influence multiple aspects of raw-mineral sustainability. The Austrian Science Fund (FWF) sponsored a project to investigate the cause of the fines by studying blast fragmentation through small-scale blast tests and numerical simulations. The paper covers the experimental part of the project focusing on internal blast-induced fracturing and related mechanisms. The blast tests were done by blast-loading confined granite and mortar cylinders. The blast-driven dynamic cracking at the end face of the cylinder opposite to the initiation point was filmed with a high-speed camera. Following analyses covered internal crack patterns, fracture surfaces, and sieving of the blasted cylinders to quantify the amount of fine material created. The internal crack patterns and fracture surfaces were analysed by means of computer tomography (CT) and scanning-electron microscopy (SEM). The CT scans show that the amount of explosive charge affects the changing of the topological features of the crack patterns along the cylinder. They also depict different deformation zones around the blast-hole wall with respect to the blasted material and the amount of charge. Although fracture surfaces of larger fragments do not clearly differ in measured roughness and curvature, the SEM scans of smaller fragments show clear difference in fracture surfaces with respect to the blasted material and the amount of charge. SEM scans of thin sections extracted from the blasted cylinders show different fracture features that could be related to the branching/merging mechanism.

Physical review materials 5(11), 113609 (2021). doi:10.1103/PhysRevMaterials.5.113609, Thermal expansion of materials is of fundamental practical relevance and arises from an interplay of several material properties. For nanocrystalline materials, accurate measurements of thermal expansion based on high-precision reference dilatometry allow inferring phenomena taking place at internal interfaces such as vacancy annihilation at grain boundaries. Here we report on measurements obtained for a severely deformed 316L austenitic steel, showing an anomaly in difference dilatometry curves which we attribute to the exceptionally high density of stacking faults. On the basis of ab intio simulations we report evidence that the peculiar magnetic state of the 316L austenitic steel causes stacking faults to expand more than the matrix. So far, the effect has only been observed for this particular austenitic steel but we expect that other magnetic materials could exhibit an even more pronounced anomaly., Published by APS, College Park, MD

According to Notker Slenczka, Jesus redefined the early Jewish understanding of God so radically that the Old Testament could not remain an adequate expression of the Christian idea of God. Moreover, in the light of historical criticism, the messianic promises of the OT could no longer be read as prophetic references to Jesus, either. The OT could hence only be seen as revelation to Jews; for Christians, however, it is valuable as paradigmatic expression of human reality and their necessity of salvation only, and to them authentic information about redemption is provided only by the New Testament. The essay discusses this position and defines a possible Christian view on the relation between Old and New Testament based on the insight that Jesus’ redefinition of the image of God can only be understood in the light of the history of God’s self-revelation to Israel, of which Jesus is a part; from a Christian perspective, the words, actions and fate of Jesus then also shed new light on the history of God’s self-revelation to Israel.

Der Ausdruck „gerechter Frieden“ hat einen kaum verdeckten polemischen Kern. Er soll namlich einen grundsatzlichen Wendepunkt protestantischer Friedensethik markieren. Habe der friedensethische Diskurs sich bisher am Leitbild des gerechten Krieges orientiert, so musse jetzt diese Fixierung uberwunden werden zugunsten des Leitbilds „gerechter Frieden“, also der Herstellung und Erhaltung nachhaltig friedlicher, durch Gerechtigkeit stabilisierter inner- und zwischenstaatlicher Lebensverhaltnisse.

Die Bedeutung von Sicherheit fur das friedliche Zusammenleben ist den biblischen Traditionen nicht unbekannt. Den durch die Wuste ziehenden Israeliten wird verheisen, dass sie im gelobten Land „sicher wohnen“ werden (vgl. z. B. Lev 26,5; Dtn 12,10). Und im babylonischen Exil gehort zu der eschatologisch aufgeladenen Vision der Ruckkehr der Deportierten regelmasig die Perspektive einer gesicherten Existenz (vgl. z. B. Jer 23,6; 32,37). In der besonders aussagekraftigen Passage Ez 34,25-31 wird im Rahmen des „Bundes des Friedens“, den Gott fur die Ruckkehr verspricht, die Sicherheit sogar im Zusammenspiel vielfaltiger Faktoren entfaltet: nach ausen als Befreiung aus und Bewahrung vor Fremdbestimmung durch andere Volker, nach innen als Schutz vor Gefahrdungen (z. B. „bose Tiere“ oder Durre) und als Sicherung der Lebensgrundlagen (Fruchtbarkeit des Landes, kein Hunger).

In September 2017, the feast of the Exaltation of the Holy Cross in Trier was celebrated ecu­menically. It is within this context that this contribution discusses central traits of Luther’s theology of the cross based on the 1518 Heidelberg Disputation and the 1519 Sermon on Preparing to Die (Sermon von der Bereitung zum Sterben). It then identifies important conse­quences of Luther’s focus on the cross in Christology, his understanding of the Lord’s Supper, and in ethics, and draws reception-historical lines to modern Lutheranism. At the end, consi­derations as to the ecumenical relevance of the theology of the cross are presented.

Has the search for "consensus" in the dialogues of the Christian churches turned out to be a dead end street? Should the churches not rather start to emphasize their own respective "profile" more strongly? The paper examines Ulrich Kort-ner's thesis that recently a "paradigm change" "from ecumenism of consensus to ecumenism of differences" has taken place. According to Kortner, the plurality of denominations is at the same time a negative result of sinful selfishness, as it is a positive expression of the variety of creation and the polyphony of the Holy Spirit's gifts. Thus, neither simply conserving denominational identity, nor trying to overcome the separation of churches is good or bad in itself. Ecumenical dialogues, as Kortner puts it, should aim at leading churches to acknowledge that they need each other "to become whole", and to find so much common ground, that they can share Holy communion. The search for visible unity of the "people of God", however, according to Kortner, is limited by the fact that the Jews necessarily are part of this people. With reference to the dialogues of the churches, nevertheless, the paper interprets Kortner's concept as rather continuing than overcoming the idea of "ecumenism of consensus".

Why should we be interested in the Filioque problem? Why should we spend time on dealing with one of the most subtle subtleties of the doctrine of Trinity as the question whether in the eternal life of God the Holy Spirit “proceeds” “from the Father”, “from the Father alone”, “from the Father through the Son” or “from the Father and the Son” apparently is? And why should we put effort into understanding a detail within the tradition of the Nicean-Constantipolitanean Creed, a Creed which is (at least in German Lutheran churches) almost never ever used? Might there a question be imagined that seems to be more irrelevant to our present problems and tasks in Church and theology?

Vacancies, dislocations, and interfaces are structural defects that are deliberately introduced into solids during grain refinement processes based on severe plastic deformation (SPD). Specific combinations of these defects determine the improved mechanical properties of the obtained ultrafine-grained materials. High-precision, non-equilibrium dilatometry, i.e., measurement of the irreversible macroscopic length change upon defect annealing, provides a powerful technique for the characterization and the study of the kinetics of these defects. It is applied to determine absolute concentrations of vacancies, to characterize dislocation processes, and to assess grain boundary excess volume in pure, FCC and BCC ultrafine-grained metals processed by SPD.