October 2017

Models for calculating monthly average solar radiation from air temperature in Swaziland

Solar radiation is an important energy source for mankind. Accurate data of solar radiation levels for a particular location is vital for optimum operation of solar energy transducers such as photovoltaic cells and solar thermal collectors. In this work, it is shown a linear relationship exist between monthly average temperatures and solar radiation in Swaziland. The correlation has been utilized to develop two...

Author(s): Mgidi D. Dlamini, Alakaparampil J. Varkey and Simiso K. Mkhonta

October 2017

A study of semi-annual variation of residual geomagnetic field and its association with solar and geomagnetic activity

The semi-annual variation of the residual H and Z components of geomagnetic field was studied by analyzing magnetograms with sixty-one years data. Mean monthly residual H- and Z-component field (Hdiff and Zdiff) variations were computed using appropriate technique. Semi-annual variation exhibited Hdiff peaks in the equinoxes, which for low latitudes, was higher during March/April than in September/October. In the mid...

Author(s): Egba Ibeabuchi G., Kalu Florence D., Okwesili Agatha N. and Okpala Kingsley C.,

October 2017

Radioactivity in building materials in Saudi Arabia: An overview of experimental method and Monte Carlo N-Particle (MCNP) calculation

The aims of this work were clearly to assess the norms of radiation protection for building residents against natural radioactivity. This was done through measurement of natural radioactivity in building materials using gamma ray spectrometer. The annual effective dose (HR) linked to natural radioactivity was computed to estimate the radiation hazard in building materials. Obtained concentrations of these natural...

Author(s): H. Alshammari, Abdulrahman Alghamdi and Ahmed Algammidi