March 2014

Numerical modeling of transients in gas pipeline

A set of equations governing an isothermal compressible fluid flow is analytically and numerically analyzed. The obtained equations are written in characteristic form and resolved by a predictor-corrector lambda scheme for the interior mesh points. The method of characteristics (MOC) is used for the boundaries. Advantages of explicit form of these schemes and the flexibility of the MOC are used for an isothermal fast...

Author(s): Mohand  KESSAL, Rachid BOUCETTA, Mohammed ZAMOUM and  Mourad TIKOBAINI

March 2014

Application of the erbium-doped fiber amplifier (EDFA) in wavelength division multiplexing (WDM) transmission systems

In the work, characteristics of the erbium-doped fiber amplifier (EDFA) are investigated. The amplification and noise figure dependences on different EDFA parameters in a 2.5 Gbit/s one-channel WDM transmission system are simulated and measured. Additionally, simulation of a four-channel 2.5 Gbit/s WDM system containing in-line amplifiers of the type was done in order to investigate the EDFA performance in multichannel...

Author(s): G. Ivanovs, V. Bobrovs, S. Olonkins, A. Alsevska, L. Gegere, R. Parts, P. Gavars and G. Lauks

March 2014

Investigation of Kenyan bentonite in adsorption of some heavy metals in aqueous systems using cyclic voltammetric techniques

Potential application of Kenyan bentonite for adsorption of iron, cobalt, copper, nickel and zinc and for analysis of electroactive species in water from a polluted water course using a 3-electrode potentiostat and cyclic voltammetry was studied. Polished carbon graphite electrodes were used either bare or modified with Kenyan bentonite using an electrochemically inert adhesive to a thickness of about 0.8 mm. These were...

Author(s): Damaris Mbui, Duke Omondi Orata, Graham Jackson and David Kariuki