Self-Insurance and Self-Protection as Public Goods

Many public goods like lighthouses and fire departments do not provide direct utility but act as insurance devices against shipwreck and destruction. They either diminish the size and/or the probability of the loss. We extend the public good model with this insurance aspect and generalize Samuelson?s efficient allocation rule when self-insurance and self-protection expenditures are pure public goods. Some comparative static results with respect to changes in income and risk behavior are derived. We analyze the interaction of private market insurance with the public good level, both for efficient provision and for private provision equilibria. The privately provided levels of self- insurance and self-protection decrease when market insurance is available, which suggests that the state should invest more in preventing not insurable risks like wars. Additionally, the state should focus on self-protection expenditures if those are better observable than private self-protection effort. --Self-insurance,self-protection,efficient provision of public goods,private provision of public goods,market insurance

Optimal Prandtl number for heat transfer in rotating Rayleigh-Benard convection

Numerical data for the heat transfer as a function of the Prandtl (Pr) and Rossby (Ro) numbers in turbulent rotating Rayleigh-Benard convection are presented for Rayleigh number Ra = 10^8. When Ro is fixed the heat transfer enhancement with respect to the non-rotating value shows a maximum as function of Pr. This maximum is due to the reduced efficiency of Ekman pumping when Pr becomes too small or too large. When Pr becomes small, i.e. for large thermal diffusivity, the heat that is carried by the vertical vortices spreads out in the middle of the cell, and Ekman pumping thus becomes less efficient. For higher Pr the thermal boundary layers (BLs) are thinner than the kinetic BLs and therefore the Ekman vortices do not reach the thermal BL. This means that the fluid that is sucked into the vertical vortices is colder than for lower Pr which limits the efficiency of the upwards heat transfer.Comment: 5 pages, 6 figure

Thermal Properties of a Hot Pion Gas beyond the Quasiparticle Approximation

Within the Matsubara formalism we derive expressions for the pion self-energy and the two-pion propagator in a hot pion gas. These quantities are used to selfconsistently calculate the in-medium $\pi\pi$ amplitude beyond the quasiparticle approximation (QPA). The results are shown to differ significantly from QPA-based calculations. We also examine the impact of chiral constraints on the $\pi\pi$ interaction in a chirally improved version of the J\"ulich $\pi\pi$ model.Comment: 12 pages LaTex (3 figures uuencoded

Knudsen gas provides nanobubble stability

We provide a model for the remarkable stability of surface nanobubbles to bulk dissolution. The key to the solution is that the gas in a nanobubble is of Knudsen type. This leads to the generation of a bulk liquid flow which effectively forces the diffusive gas to remain local. Our model predicts the presence of a vertical water jet immediately above a nanobubble, with an estimated speed of $\sim3.3\,\mathrm{m/s}$, in good agreement with our experimental atomic force microscopy measurement of $\sim2.7\,\mathrm{m/s}$. In addition, our model also predicts an upper bound for the size of nanobubbles, which is consistent with the available experimental data

Surface bubble nucleation phase space

Recent research has revealed several different techniques for nanoscopic gas nucleation on submerged surfaces, with findings seemingly in contradiction with each other. In response to this, we have systematically investigated the occurrence of surface nanobubbles on a hydrophobised silicon substrate for various different liquid temperatures and gas concentrations, which we controlled independently. We found that nanobubbles occupy a distinct region of this phase space, occurring for gas concentrations of approximately 100-110%. Below the nanobubble phase we did not detect any gaseous formations on the substrate, whereas micropancakes (micron wide, nanometer high gaseous domains) were found at higher temperatures and gas concentrations. We moreover find that supersaturation of dissolved gases is not a requirement for nucleation of bubbles.Comment: 4 pages, 4 figure

Business Models in the context of carbon mitigation: New Questions and Approaches illustrated by the Example of Energy Performance Contracting in Germany

The German government has set ambitious climate protection targets to limit global warming. The goal is to achieve an energy efficient and almost climate-neutral building stock by 2050. This will require, among other actions, a reduction of the primary energy demand of buildings by up to 95% by the end of 2050. In order to achieve an almost climate-neutral building stock, measures for deep energy retrofit are required. In addition to an existing financial demand, there are additional barriers to the expansion of activities to improve the energy performance and to reduce greenhouse gas (GHG) emissions of the existing building stock. One way to overcome these barriers are novel business models such as Energy Performance Contracting (EPC). The question arises as to whether and how the reduction of GHG emissions can be taken into account in the savings guarantees as they are typical for EPCs. This and other questions are addressed in the paper using conjoint analysis. Among other results, it is pointed out that specific approaches are required for different target groups such as the public sector and private homeowners. Finally, recommendations for further action are given. The presented partial results are drawn from the research work "Analysis of business models with regard to their potential for GHG reduction and energy efficiency of buildings"

Concurrent TNFRSF1A R92Q and pyrin E230K mutations in a child with multiple sclerosis

We report a 16-year-old female patient with a severe course of multiple sclerosis and concomitant symptoms suggestive of a hereditary autoinflammatory disease. Genetic analyses revealed that she inherited a TNFRSF1A R92Q mutation from her mother and a pyrin E230K mutation from her father. To our knowledge, this is the first report of a patient with severe childhood multiple sclerosis and mutations in two genes which predispose to hereditary autoinflammatory disorders. We speculate that these mutations contribute to early multiple sclerosis manifestation and enhance the inflammatory damage inflicted by the autoimmune response