Novel Porous Polymorphs of Zinc Cyanide with Rich Thermal and Mechanical Behavior

We investigate the feasibility of four-connected nets as hypothetical zinc cyanide polymorphs, as well as their thermal and mechanical properties, through quantum chemical calculations and molecular dynamics simulations. We confirm the metastability of the two porous phases recently discovered experimentally (Lapidus, S. H.; et al. J. Am. Chem. Soc. 2013, 135, 7621-7628), suggest the existence of seven novel porous phases of Zn(CN)2, and show that isotropic negative thermal expansion is a common occurrence among all members of this family of materials, with thermal expansion coefficients close to that of the dense dia-c phase. In constrast, we find a wide variety in the mechanical behavior of these porous structures with framework-dependent anisotropic compressibilities. All porous structures, however, show pressure-induced softening leading to a structural transition at modest pressure.Comment: Chem. Mater. 201

Nonparametric estimation of the conditional distribution of the inter-jumping times for piecewise-deterministic Markov processes

This paper presents a nonparametric method for estimating the conditional density associated to the jump rate of a piecewise-deterministic Markov process. In our framework, the estimation needs only one observation of the process within a long time interval. Our method relies on a generalization of Aalen's multiplicative intensity model. We prove the uniform consistency of our estimator, under some reasonable assumptions related to the primitive characteristics of the process. A simulation example illustrates the behavior of our estimator

A model of the anchoring effect in dichotomous choice valuation with follow-up.

This paper focuses on modelling and estimating the starting point bias in closed-ended follow-up questions, where several bids are presented successively, depending on previous answers. Although the contingent valuation literature took off in the last decade, there is only one study modelling the starting point bias. We propose a new modelling of this anchoring effect based on the assumption the first proposed bid has a direct influence on the individual's willingness-to-pay, i.e respondents modify their willingness-to-pay when presented with the first bid just before they answer the first question. Monte Carlo results support the specification of our model. An application is provided based on data from a contingent valuation study conducted concerning air quality in Strasbourg.Contingent valuation, willingness-to-pay, binary-choice, anchoring effect.

Prevention and Compensation of Muddy Flows: Some Economic Insights.

Recent surveys report the increasing number of muddy flows in many areas, and point out the fact that agricultural practices (among others) influence significantly the risk and severity of muddy flows. In this paper, we investigate the economic incentives that can be given to the farmer to adopt different practices. We propose an original economic instrument that entails an `ambient tax', voluntary revelations and a compensation fund. Because of the authorities' difficulties to be informed of each farmer's individual efforts, the tax cannot depend on the individual but on the collective level of efforts. However, each agent may lower his tax payment by revealing his individual efforts to the regulator so that high efforts may be rewarded compared to low ones. The tax revenue is used to supply a fund that is dedicated to the compensation of victims if a muddy flow occurs. hence it is possible to simultaneously increase the incentives for farmers to adopt more environmentally friendly practices and to improve the compensation of victims without mitigating their incentives to protect themselves against the risk of muddy flow.muddy flow, natural disasters, economic incentives, ambient tax, insurance, compensation fund.