Search

The activation of carbon from Manihot Esculenta (cassava) peels as a sustainable biomass precursor was explored for application in supercapacitors (SCs); demonstrating a cheap and sustainable environmental friendly source of carbon materials for potential application as electrode materials for SC. The activation was carried out with three different activating agents namely potassium hydroxide (KOH), potassium bicarbonate (KHCO3) and potassium chloride in sodium thiosulphate (KCl–Na2S2O3). The obtained activated carbon (AC) material exhibited SSA up to 828 ​m2 ​g−1 for the KOH activation and the electrodes fabricated revealed a specific capacitance (CSP) (300 ​F ​g−1 at 0.5 ​A ​g−1), excellent rate capability and cycling stability (98% capacitance retention after 5000 cycles) in 6 ​M KOH aqueous solution. The study demonstrated an efficient and sustainable approach for high performance SCs by using biomass as a viable source of the carbon material for SC applications.

The corrosion behavior of mild steel in carbonated drinks produced by Nigerian Breweries (Fanta, Sprite and Coke) was studied in the presence and absence of an eco-friendly inhibitor, Chrysophyllum albidum using Potentiodynamic polarization technique at 25 °C. Results showed that Chrysophyllum albidum reduced the current density (icorr), which in turn means that the corrosion rate was reduced significantly. The inhibition efficiency was found to be 93%, 78.6% and 87.5% for Fanta, Sprite and Coke respectively. The study also showed that Chrysophyllum albidum functioned as a mixed-type corrosion inhibitor in the three environments studied and therefore presents it as a long-term inhibitor for the corrosion of mild steel.

A one-reflector solar oven for solar panel lamination was constructed using locally available and low cost materials. The oven was tested for thermal performance through three tests. The first test was a no load test with the oven positioned to face 180 0 S. This test produced a maximum oven laminating platen temperature of 118 0 C at an ambient temperature of 33 0 C and solar irradiance of 1046W/m 2 . A second no-load test was carried out with the oven being turned every 30 minutes to face the sun through a method which we discovered and termed manual shadow tracking. Manual shadow tracking is a method of turning a box type solar oven to face the sun by aligning the bottom edge of the oven with the edge of the oven's shadow. The second no-load test produced a maximum temperature of 124 0 C at an ambient temperature of 36 0 C and solar irradiance of 1010W/m 2 . With these values, the first figure of merit for the oven was calculated as 0.09. A third test which was carried out with the oven loaded with a solar panel to be laminated, produced a maximum temperature of 110.5 0 C at an ambient temperature of 35 0 C and solar irradiance of 1021W/m 2 . A 160W solar panel was

This paper presents a mathematical model of the Collect and Discharge Tank unit of the rain driven hydro power generator currently being designed using the University of Port Harcourt's faculty of science building at Ofrima, Abuja Campus. The model revealed that over 2.0KW of power can be generated using rain water collected from the building, and that a minimum of 3,751 gallons storage capacity tank is needed to make sure that the unused water accumulated from a 0.6 inches per hour of rainfall is effectively stored if rainfall lasts for 33.33 minutes. This means that for the tank to effectively serve its purpose when rainfall at the rate of 0.6 inches per hour lasts for over 33.33 minutes, a larger capacity size of tank is needed, or the hydro power generating system is redesigned to generate power greater than 2.0KW.

No Abstract.Nigerian Journal of Physics Vol. 20 (1) 2008: pp.1-5

The stability of a binary mixture of a chemically reacting incompressible fluid in plane couette flow is considered with respect to a two-dimensional infinitesimal disturbance. The eighenvalues are found with the aid of microcomputer. Neutral stability curves for various Schmidt numbers at Reynolds numbers up to 150 are obtained by Gallagher method. It is found that the principle of the exchange of stabilities holds for this problem. Thus, using the basic orthogonal functions, the differential equations are reduced to a set of paired matrix equations with the conclusion that all fluids are unstable at different values of stability parameter C=1.40 x 10 to 2.0 x 10 for wave number (a) = 0.2 to 2 (based on half-channel width and half the relative velocity of the plates). Keywords : Incompressible fluid, binary mixture, wave number, couette flow and stability parameter. Nigerian Journal of Physics Vol. 18 (2) 2006: pp. 155-160

Cathodoluminescence emission spectra and luminescence excitation spectra of Mn2+in calcites, dolomites, magnesites, a manganocalcite and a rhodochrosite have been measured at both room temperature and 77 K. Ligand-field parameters have been calculated from the excitation spectra which reflect the size of the metal cation site in which the Mn2+ion resides. The technique of luminescence excitation spectra has enabled the absorption profile of Mn2+in Mg and Ca sites in dolomite to be separately determined. The variation of the distribution of Mn2+between Mg and Ca sites in dolomites is demonstrated and discussed in terms of a simple model. It is concluded that the distribution of Mn2+in dolomites may well provide information about its conditions of formation and/or subsequent alteration.