December 2008

Prospect assessment and risk analysis: Example from Niger Delta, Nigeria Basin

Exploring for oil and gas is a risky business. Risk is the chance of failure, and there are many more dry wildcats than there are wells that make discoveries. The quantification of risk in relation to reward is one of the main benefits of formal assessments of undiscovered oil and gas potentials, but in this paper we consider only the geologic existence risks, and environmental risks.   Key...

Author(s): Aigbedion, I., Iyayi, S. E. and Agbeboh, G. U.

December 2008

Photodestruction and COD removal of toxic dye erioglaucine by TiO2-UV process: Influence of operational parameters

Aqueous solutions of Erioglaucine, a hazardous dye, are photodegraded under ultraviolet light using TiO2 as catalyst. The process has been carried out at different pHs, amounts of catalyst, concentrations of the dye, and effects of the electron acceptor H2O2. It is found that under the influence of TiO2 as catalyst the coloured solution of the dye Erioglaucine becomes colourless and the process follows...

Author(s): Rajeev Jain and Shalini Sikarwar

December 2008

Dependence of temperature variation of the Jahn-Teller potential well splitting and phase transition temperature in CuxZn1-xTiF6.6H2O crystals on Cu2+ ion concentration, x

The energy Eo by which one of the three Jahn-Teller potential wells becomes lower than the other two in Cu2+:ZnTiF6.6H2O single crystal at phase transition temperature, Tcl are determined at temperatures below Tcl for different Cu2+concentrations from the electron paramagnetic resonance (EPR) spectra. As the sample is cooled, it is found that for high Cu2+ concentration, Eo increases below...

Author(s): Dilip K. De and J. B. Yerima

December 2008

Numerical simulation of a one-dimensional shock tube problem at supercritical fluid conditions

The numerical computation of supercritical fluid flows is extremely challenging because of the complexity of the physical processes and the disparity of the space and time scales involved. Supercritical fluids exhibit large density fluctuations especially very close to the critical region. In this region, the perfect gas law is no longer valid and has to be replaced by a specific equation of state (EoS) as, for...

Author(s): Hatem Ksibi and Ali Ben Moussa