Evaluation Of Polymeric Coatings On Their Efficiency Of Inhibiting The Adhesion Of Inorganic Scale

The use of polymer coatings allows modulating wettability and can contribute decisively to mitigate the formation of scale in pipes and equipment. In this work critical surface energy (CSE) and surface free energy (SFE) were determined for several polymer coatings (epoxy phenol novolac resins and fluoropolymers), aiming the evaluation of their antifouling capacity against brines reproducing formation waters from pre salt wells. Coatings with lower values for SFE and CSE presented the lowest degree of fouling as determined by wet analysis using inductively coupled plasma atomic emission spectroscopy (ICP - AES).9

Love kills: Simulations in Penna Ageing Model

The standard Penna ageing model with sexual reproduction is enlarged by adding additional bit-strings for love: Marriage happens only if the male love strings are sufficiently different from the female ones. We simulate at what level of required difference the population dies out.Comment: 14 pages, including numerous figure

CVD of CrO2: towards a lower temperature deposition process

We report on the synthesis of highly oriented a-axis CrO2 films onto (0001) sapphire by atmospheric pressure CVD from CrO3 precursor, at growth temperatures down to 330 degree Celsius, i.e. close to 70 degrees lower than in published data for the same chemical system. The films keep the high quality magnetic behaviour as those deposited at higher temperature, which can be looked as a promising result in view of their use with thermally sensitive materials, e.g. narrow band gap semiconductors.Comment: 13 pages, 4 figure

Chaos and Synchronized Chaos in an Earthquake Model

We show that chaos is present in the symmetric two-block Burridge-Knopoff model for earthquakes. This is in contrast with previous numerical studies, but in agreement with experimental results. In this system, we have found a rich dynamical behavior with an unusual route to chaos. In the three-block system, we see the appearance of synchronized chaos, showing that this concept can have potential applications in the field of seismology.Comment: To appear in Physical Review Letters (13 pages, 6 figures