Super-heavy fermion material as metallic refrigerant for adiabatic demagnetization cooling

Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, as the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with $^3$He gas are widely used for cooling below 1 Kelvin. However, usage of the gas is being increasingly difficult due to the current world-wide shortage. Therefore, it is important to consider alternative methods of refrigeration. Here, we show that a new type of refrigerant, super-heavy electron metal, YbCo$_2$Zn$_{20}$, can be used for adiabatic demagnetization refrigeration, which does not require 3He gas. A number of advantages includes much better metallic thermal conductivity compared to the conventional insulating refrigerants. We also demonstrate that the cooling performance is optimized in Yb$_{1-x}$Sc$_x$Co$_2$Zn$_{20}$ by partial Sc substitution with $x\sim$0.19. The substitution induces chemical pressure which drives the materials close to a zero-field quantum critical point. This leads to an additional enhancement of the magnetocaloric effect in low fields and low temperatures enabling final temperatures well below 100 mK. Such performance has up to now been restricted to insulators. Since nearly a century the same principle of using local magnetic moments has been applied for adiabatic demagnetization cooling. This study opens new possibilities of using itinerant magnetic moments for the cryogen-free refrigeration

Plautus and His Dramatic Successors in the Republican Period

This chapter discusses the standing of Plautus in the middle to late Republican period, when his plays were popular with audiences, were studied by scholars, and were points of reference for other dramatists. In particular, this contribution analyzes reactions by Plautus's dramatic successors in his own dramatic genre (fabula palliata) and related ones (fabula togata, fabula Atellana) to Plautine comedy, using the motif of the contrast between town and country as a paradigmatic case study

Molucrum bei Festus und die Zubereitung der mola salsa durch die Vestalinnen

Im Lemma molucrum gibt Festus fünf verschiedene Bedeutungserklärungen, die bislang in der Forschung einzeln betrachtet wurden, häufig unter der Annahme von Entlehnungen aus dem Griechischen. Es wird gezeigt, dass einige Bedeutungen in den Kontext der archaischen Getreideverarbeitung weisen, von der sich Spuren in der Herstellung der mola salsa durch die Vestalinnen finden. Bei molucrum handelt es sich um ein auf einer Vorstufe des literarischen Lateins gebildetes Wort, dessen Basisbedeutung‚*Gerät zum Mahlen, Mahlzeug‘ ist