Adsorption hysteresis and capillary condensation in disordered porous solids: a density functional study

We present a theoretical study of capillary condensation of fluids adsorbed in mesoporous disordered media. Combining mean-field density functional theory with a coarse-grained description in terms of a lattice-gas model allows us to investigate both the out-of-equilibrium (hysteresis) and the equilibrium behavior. We show that the main features of capillary condensation in disordered solids result from the appearance of a complex free-energy landscape with a large number of metastable states. We detail the numerical procedures for finding these states, and the presence or absence of transitions in the thermodynamic limit is determined by careful finite-size studies.Comment: 30 pages, 18 figures. To appear in J. Phys.: Condens. Matte

Uneven Development, Crypto-regionalism, and the (Un-)tethering of Nature in Quebec

Since emerging in 2009, cryptocurrencies, such as bitcoin, have captured the imaginations of many investors and users in accumulating private wealth detached from government control and oversight. This article examines how the rise of bitcoin has particular geographies and trajectories of uneven development across the globe. The generation (or mining ) of cryptocurrencies is computationally-intensive, requiring computer hardware, cool air and cheap energy. Adopting the case study of Quebec, Canada, we show how these variables interact to produce a relationship between digital currencies, economic imaginaries and space in the regions where cryptomining is clustered. We argue that these new geographies of cryptocurrency mining leave residual marks on the regions where they are located but remain highly mobile moving from location to location in search of the cheap energy that supports private accumulation. Adopting an illustrative case study of Quebec, Canada, we work to render visible the materiality of cryptocurrencies, such as bitcoin. Far from existing both nowhere and everywhere, the generation of bitcoin is foregrounded in local contexts and regional economic imaginaries with both spatial and social implications for the cities and towns where cryptomining takes place. We conclude with a call for further research into this emergent crypto-regionalism and its consequences

Spontaneous comparisons with others in gay men´s judgements of HIV risk

In studies on &lsquo;unrealistic optimism&rsquo; (UO), when people are asked questions designed to make them compare their risk of experiencing an undesirable event with that of the average person, they tend to respond that their risk is lower. This study investigated whether comparisons of own and others&rsquo; risk also occur spontaneously, unprovoked by such questions. Gay men uninfected with HIV (n&frac14;50) were asked to think aloud about their risk of becoming infected; their comments were audiotaped and analysed. Over half the men added comments relating to others&rsquo; risk. The phrasing of these comments and the reported basis for them are described. The men represented others&rsquo; risk as relatively high, own risk as relatively low. In the case of onethird of the men, it seemed possible to be confident that a comparison was being made. The findings suggest that comparisons of own and others&rsquo; risk do occur spontaneously and that, while the judgements made in UO studies do not capture all the characteristics of those made spontaneously, they resemble them in important ways.<br /