Simple three-state lattice model for liquid water

The Journal of Chemical Physics, 2011

The Journal of Chemical Physics, 2009

The Bell–Lavis model for liquid water is investigated through numerical simulations. The lattice-gas model on a triangular lattice presents orientational states and is known to present a highly bonded low density phase and a loosely bonded high density phase. We show that the model liquid-liquid transition is continuous, in contradiction with mean-field results on the Husimi cactus and from the cluster variational method. We define an order parameter which allows interpretation of the transition as an order-disorder transition of the bond network. Our results indicate that the order-disorder transition is in the Ising universality class. Previous proposal of an Ehrenfest second order transition is discarded. A detailed investigation of anomalous properties has also been undertaken. The line of density maxima in the HDL phase is stabilized by fluctuations, absent in the mean-field solution.

Journal of Physical Chemistry B, 2011

Beiträge zum Tag der Niederösterreichischen Landesarchäologie, 2024

Ancient Economies in Comparative Perspective, M. Frangipane, M. Poettinger, B. Schefold eds., Frontiers in economic history, Springer, 2022

Before we can set about examining the economies and political economies in preindustrial, pre-capitalist and pre-mercantile societies, we must set aside all the usual categories we automatically use and try to understand the real bases of economic thought in those societies. It is certainly difficult for us to understand and even conceive forms of economic goals and relations that are different from the modern or contemporary ones with which we are familiar, and which refer to the economy as a system of 'rational actions' aimed at achieving maximum output with minimum effort. In today's terms, economic rationale is independent of politics and social ethics and aims at producing 'wealth', determining the 'value' of goods based on their 'scarcity' and of the rules established by the interplay of market forces. Precisely on account of our difficulty in understanding different types of rationales, the debate on ancient economies among most scholars has focused on the contrast between those who tend to see 'the first expressions of rational economic behaviour' appearing very early on, in the earliest Near Eastern societies, and those who tend to deny any recognisable form of economic rationality before the Greeks and Romans (see the discussion on this issue in Steinkeller 2015). I think, however, that this is not a matter of 'rationality', since, as Monika Poettinger has already pointed out, rationality as 'the effective use of means towards an end' has always existed in any economic action, but 'in every epoch it would be characterised by its own means and its own ends' (Poettinger 2013, 143-146). This is crucial to understand the profound differences between the political economies of different, sometimes very different, societies. The aims pursued by economic actions or strategy in early formative societies with some kind of central government or leadership may ultimately have been not only, or

2021