Vapor–Liquid Equilibria of Nitrogen + Diethyl Ether and Nitrogen + 1,1,1,2,2,4,5,5,5-Nonafluoro-4-(trifluoromethyl)-3-pentanone by Experiment, Peng–Robinson and PC-SAFT Equations of State

The saturated liquid line of the systems nitrogen (N2) + diethyl ether and N2 + 1,1,1,2,2,4,5,5,5-nonafluoro-4-(trifluoromethyl)-3-pentanone (Novec 649) is measured along three isotherms, that is, 390, 420, and 450 K and 360, 390, and 420 K, respectively. The employed gas solubility apparatus, based on the synthetic method, allows to measure points up to the critical region of these mixtures. The experimental data are used to correlate the Peng–Robinson and PC-SAFT equations of state (EOS). For the parametrization of the system, N2 + diethyl ether the Peng–Robinson EOS is combined with the Huron–Vidal mixing rule and the non-random two-liquid (NRTL) excess Gibbs energy model; for the system N2 + Novec 649 the quadratic mixing rule is used

Renormalizability, fundamentality and a final theory: The role of UV-completion in the search for quantum gravity

Principles are central to physical reasoning, particularly in the search for a theory of quantum gravity (QG), where novel empirical data is lacking. One principle widely adopted in the search for QG is UV completion: the idea that a theory should (formally) hold up to all possible high energies. We argue---/contra/ standard scientific practice---that UV-completion is poorly-motivated as a guiding principle in theory-construction, and cannot be used as a criterion of theory-justification in the search for QG. For this, we explore the reasons for expecting, or desiring, a UV-complete theory, as well as analyse how UV completion is used, and how it should be used, in various specific approaches to QG

Hints towards the Emergent Nature of Gravity

A possible way out of the conundrum of quantum gravity is the proposal that general relativity (GR) is not a fundamental theory but emerges from an underlying microscopic description. Despite recent interest in the emergent gravity program within the physics as well as the philosophy community, an assessment of the theoretical evidence for this idea is lacking at the moment. We intend to fill this gap in the literature by discussing the main arguments in favour of the hypothesis that the metric field and its dynamics are emergent. First, we distinguish between microstructure inspired from GR, such as through quantization or discretization, and microstructure that is not directly motivated from GR, such as strings, quantum bits or condensed matter fields. The emergent gravity approach can then be defined as the view that the metric field and its dynamics are derivable from the latter type of microstructure. Subsequently, we assess in how far the following properties of (semi-classical) GR are suggestive of underlying microstructure: (1) the metric's universal coupling to matter fields, (2) perturbative non-renormalizability, (3) black hole thermodynamics, and (4) the holographic principle. In the conclusion we formalize the general structure of the plausibility arguments put forward.Comment: 36 pages, v2: minor additions, references added. Journal version in Studies in History and Philosophy of Modern Physic

Kriterien für den Anbau von Weizen Rubrik Forschung Forschung aus biologisch-dynamischer Züchtung. Die Back- oder Verarbeitungsqualität

In diesem Bericht werden Ergebnisse präsentiert, die auf langjährigen Untersuchungen mit dem sogenannten Optimierten-Backtest (OBT) und Öko-Weizensorten basieren. Mit der Optimierung konnte gezeigt werden, dass eine verbesserte Teigknetung zu sehr hohen Volumenausbeuten führt. Durch Kenntnis der Backqualität biodynamischer Sorten kann mit den Proteinwerten die Backqualität in bestimmten Grenzen zur Qualitätssicherung geschätzt werden. Die genannten Details sind inzwischen auch für konventionelle Weizensorten bestätigt worden

Mathematikmaterialien mit Berufsfeldbezug in der Sekundarstufe II

Welche mathematikhaltigen Situationen haben Berufspersonen in Gesundheitsberufen, sozialen Berufen und pädagogischen Berufen zu gewärtigen? Dieser Forschungsfrage wurde in Interviews mit Ausbildenden und Praktizierenden in der Schweiz nachgegangen. Die sich ergebenden Themen lassen sich beispielsweise den Inhaltsbereichen „Umgang mit Potenzen“, „nichtlineare Prozesse“ und „Umgang mit Graphiken und Tabellen“ zuordnen – also längst nicht nur den zu erwartenden Kompetenzen bei proportionalen Zusammenhängen und Überschlagsrechnungen