November 2015

On solar wind speed distribution and geomagnetic activity during solar cycle 23 and the early ascending phase of solar cycle 24

This paper investigates solar wind repartition through four classes of solar events: (1) one class of quiet days (QD) caused by slow solar wind (V< 450 km/s), and three disturbed activities, where V ≥ 450 km/s, (2) recurrent wind (RW), (3) shock wind (SW), (4) fluctuating wind (FW). RW class is characterized by recurrent high solar wind extended on several solar rotations. SW class is caused by CMEs events. FW...

Author(s): Jean Louis Zerbo,, Frédéric Ouattara and Emmanuel Nanéma,

November 2015

Polylactic acid (PLA) viscoelastic properties and their degradation compared with those of polyethylene

Polyethylene (PE) films are widely used in packaging. PE is a thermoplastic manufactured from nonrenewable petroleum resources. Due to its non–biodegradability, its films have posed serious pollution problems e.g. visual pollution, blockage of gutters and drains, choking of animals etc. Suitable replacements for PE films especially for single use only, are the starch based thermoplastics such as Polylactic acid...

Author(s): Muthui Z. W., Kamweru P. K., Nderitu F. G, Hussein S. A. Golicha, Ngumbu R. and Njoroge G. N.