An efficient method of evaluating portfolio risk and return

This paper presents an efficient method to compute portfolio risk and return. Two methodologies are exposed in evaluating portfolio performance by aggregation of securities returns: the first one is based on local approximations of the compounding capitalization formula; in the alternative method, which properties are extremely useful within IAS-IFRS accounting principles, integral approximations of the amortized cost function are used. As for risk estimation, total portfolio tracking error is decomposed in summable factors directly related to benchmark asset class and portfolio weights.     

Translational diffusion of water in compacted clay systems

The translational diffusion of water in compacted clays at a high hydration level has been investigated by quasielastic neutron scattering at a time-of-flight spectrometer FOCUS (SINQ). Four compacted clays with systematic structural differences have been studied: Na-montmorillonite, Na-illite, kaolinite and pyrophyllite. The QENS experiments were performed using two different incident wavelengths in order to access a larger Q range and verify the data analysis. The translational diffusion coefficient for water in Na-montmorillonite and Na-illite are lower than those for bulk water, whereas the preliminary results for kaolinite and pyrophyllite show larger diffusion coefficient.