Boiling of the Interface between Two Immiscible Liquids below the Bulk Boiling Temperatures of Both Components

We consider the problem of boiling of the direct contact of two immiscible liquids. An intense vapour formation at such a direct contact is possible below the bulk boiling points of both components, meaning an effective decrease of the boiling temperature of the system. Although the phenomenon is known in science and widely employed in technology, the direct contact boiling process was thoroughly studied (both experimentally and theoretically) only for the case where one of liquids is becoming heated above its bulk boiling point. On the contrary, we address the case where both liquids remain below their bulk boiling points. In this paper we construct the theoretical description of the boiling process and discuss the actualisation of the case we consider for real systems.Comment: 17 page, 7 figures, accepted to Eur. Phys. J.

Essays In Empirical Asset Pricing

In this dissertation, I revisit two problems in empirical asset pricing. In Chapter 1, I propose a methodology to evaluate the validity of linear asset pricing factor models under short sale restrictions using a regression-based test. The test is based on the revised null hypothesis that intercepts obtained from regressing excess returns of test assets on factor returns, usually referred to as alphas, are non-positive. I show that under short sale restrictions a much larger set of models is supported by the data than without restrictions. In particular, the Fama-French five-factor model augmented with the momentum factor is rejected less often than other models. In Chapter 2, I investigate patterns of equity premium predictability in international capital markets and explore the robustness of common predictive variables. In particular, I focus on predictive regressions with multiple predictors: dividend-price ratio, four interest rate variables, and inflation. To obtain precise estimates, two estimation methods are employed. First, I consider all capital markets jointly as a system of regressions. Second, I take into account uncertainty about which potential predictors forecast excess returns by employing spike-and-slab prior. My results suggest evidence in favor of predictability is weak both in- and out-of-sample and limited to a few countries. The strong predictability observed on the U.S. market is rather exceptional. In addition, my analysis shows that considering model uncertainty is essential as it leads to a statistically significant increase of investors’ welfare both in- and out-of-sample. On the other hand, the welfare increase associated with considering capital markets jointly is relatively modest. However, it leads to reconsider the relative importance of predictive variables because the variables that are statistically significant predictors in the country-specific regressions are insignificant when the capital markets are studied jointly. In particular, my results suggest that the in-sample evidence in favor of the interest rate variables, that are believed to be among the most robust predictors by the literature, is spurious and is mostly driven by ignoring the cross-country information. Conversely, the dividend-price ratio emerges as the only robust predictor of future stock returns

Noise-Produced Patterns in Images Constructed from Magnetic Flux Leakage Data

Magnetic flux leakage measurements help identify the position, size and shape of corrosion-related defects in steel casings used to protect boreholes drilled into oil and gas reservoirs. Images constructed from magnetic flux leakage data contain patterns related to noise inherent in the method. We investigate the patterns and their scaling properties for the case of delta-correlated input noise, and consider the implications for the method's ability to resolve defects. The analytical evaluation of the noise-produced patterns is made possible by model reduction facilitated by large-scale approximation. With appropriate modification, the approach can be employed to analyze noise-produced patterns in other situations where the data of interest are not measured directly, but are related to the measured data by a complex linear transform involving integrations with respect to spatial coordinates.Comment: 11 pages, 2 figure

Collision of viscoelastic bodies: Rigorous derivation of dissipative force

We report a new theory of dissipative forces acting between colliding viscoelastic bodies. The impact velocity is assumed not to be large, to avoid plastic deformations and fragmentation at the impact. The bodies may be of an arbitrary convex shape and of different materials. We develop a mathematically rigorous perturbation scheme to solve the continuum mechanics equation that deals with both displacement and displacement rate fields and accounts for the dissipation in the bulk of the material. The perturbative solution of this equation allows to go beyond the previously used quasi-static approximation and obtain the dissipative force. This force does not suffer from the physical inconsistencies of the latter approximation and depends on particle deformation and deformation rate.Comment: 9 pages, 1 figure. arXiv admin note: text overlap with arXiv:1410.328