August 2009
Chromium (III) sorption from aqueous solutions using activated carbon prepared from cashew nut shells
Activated carbon prepared from cashew nut shells using potassium hydroxide activation at 850°C in N2 and CO2 atmosphere was used as an adsorbent for the removal of chromium ions from aqueous solutions. The adsorption of Cr(III) ions on activated carbon was studied. The effect of experimental parameters such as, pH of initial concentration of Cr(III) solutions, contact time, dosage of adsorbent and initial...
August 2009
Ultrasound-assisted extraction flavonoids from Lotus (Nelumbo nuficera Gaertn) leaf and evaluation of its anti-fatigue activity
In this study, flavonoids were obtained from Lotus (Nelumbo nuficera Gaertn) leaf using ultrasound-assisted extraction method (UAE). Optimum extraction conditions of flavonoids from Lotus leaf (FLL) were investigated through single factor test and orthogonal test. Its anti-fatigue activity was evaluated by swimming test. The results showed that the optimal extraction parameters were as followings: concentration of...
August 2009
Equilibrium sorption isotherm for lead (Pb) ions on hydrogen peroxide modified rice hulls
Modified rice hulls system for removing Pb (II) from aqueous solutions has been investigated. Rice hulls are agricultural waste product. The experimental condition was the modification of the rice hulls (sorbent) with different concentrations of hydrogen peroxide solution. The experimental results were fitted to the Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. The Langmuir...
August 2009
Family of surface with a common null geodesic
We analyzed the problem of finding a surfaces family through a null curve with Cartan frame. We constructed a differential equation system such that a given null curve is an isogeodesic curve on a surface. In addition, developablity along the common null geodesic of the members of surface family are discussed. The extension to ruled surfaces is also outlined. Finally, we demonstrated some interesting surfaces about...
August 2009
A new priority sequence rule for the theoretical determination of products of explosion reactions
A new priority sequence rule for the theoretical prediction of products of explosion reactions is derived from the standard enthalpies of formation of the products using the gaseous states of the relevant elements. The standard enthalpies were calculated and arranged in increasing order to form a priority sequence rule of products in the order H2O, CO, CO2, based on the fact that a compound with lower enthalpy is more...
August 2009
Theoretical studies of the effect of Ti, Zr and Hf substitutions on the electronic properties of alpha-alumina
We have investigated the electronic properties of pure Alpha-Alumina (sapphire phase) and the aluminates α-Al2-xTxO3 where T is a transition metal and stands for Ti, Zr and Hf with x = 0.5. In this study we have employed the full potential linear augmented plane wave (FPLAPW) with Generalized Gradient Approximations (GGA) based on the Density Functional Theory (DFT) as implemented in WIEN2K code. The result shows...
August 2009
Application of geophysical and geotechnical investigations in engineering site evaluation
Geophysical and geotechnical studies were conducted at a proposed Switch station facility for Telecommunication at a site in the south-eastern part of Nigeria. The aim of the study is to evaluate the sub-soil conditions and electrical properties of the soil which may have effect on the proposed mast and switch facilities system. The geophysical investigation involved the Vertical Electrical Sounding (VES) technique...
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