Modelling of dynamical effects related to the wettability and capillarity of simple and complex liquids

This Thesis explores physical phenomena characteristic for thin liquid films and small droplets of simple and complex liquids on solid substrates for which wettability and capillarity control their statical and dynamical properties. We start by discussing the general concepts of wettability and capillarity and introduce the common mathematical framework of the lubrication approximation for studies of thin liquid films and small contact angle drops. We demonstrate the derivation of the generic equation describing the evolution of a film of simple liquid from the Navier-Stokes equations. We show how this model can be further extended to incorporate various effects relevant to the case of complex liquids. The results described in the Thesis comprise three projects with the common main theme of the influence of wettability and capillarity on the statics and dynamics of the studied systems, namely (i) Evaporating sessile droplets fed through the solid substrate - a geometry that allows us to discuss steady states of the system and their role in the time evolution of freely evaporating droplets without influx in an isothermal case; (ii) The influence of a solute--dependent wettability on the stability, static and dynamical properties of thin films and drops of non-volatile mixtures, suspensions and solutions; (iii) A parameter-passing scheme between particle-based Molecular Dynamics simulations and the continuum lubrication model which allows us to discuss equilibrium properties of small polymeric droplets. We present the physical questions arising in the three systems and discuss approaches and results as well as possible extensions

Long term changes and recent state of macrozoobenthic communities along the Bulgarian Black Sea coast

The analysis of macrozoobenthic samples collected from 34 stations along the Bulgarian Black Sea shelf at depths ranging from 12 to 83 m yielded 103 taxonomic units. The average abundance established in the present study was over 5000 ind/m2 with nearly 70% dominance of the polychaetes. The number of species, Shannon-Wiener diversity index (H') and Pielou's evenness (J) were the lowest in Varna and Burgas bays, indicating that they are the most ecologically threatened areas along the Bulgarian Black Sea coast. The quantitative and qualitative data were compared to published data from the pristine period 1954-1957 and from the period 1982-1985 with intensive anthropogenic pressure. The comparison revealed an increase of the share of molluscan species and a decrease of the contribution of crustacean species in the total number of species. A 7-fold increase of the total average abundance was established compared to the pristine period 1954-1957. During the recent period the polychaetes are the most dominant group in the benthic abundance, while during the pristine period 1954-1957 the most abundant were the molluscs with nearly 61% of the total abundance. These changes in the benthic communities are attributed to the process of eutrophication. While in the pelagic environment signs of recovery have been observed, we deem that up to 1997 no such signs are valid for the benthic communities

CLINICAL TESTING OF «ALBUFAN» AND «GLUCOFAN» - INDICATOR PAPERS FOR PROTEIN AND SUGAR DEMONSTRATION IN THE URINE

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KALLIKREIN-KININ SYSTEM (KKS) AND ANGIOTENSIN CONVERTING ENZYME ACTIVITY (ACE) IN PATIENTS ON PERIODIC HA•MODIALYSIS (PHD) TREATED WITH RECOMBINANT HUMAN ERYTHROPOIETIN (rhEPO)

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