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The effects of outdoor temperature, rainfall and wind speed on the indoor radon concentration in four types of traditional hut in Kenya were investigated by performing short-term (about 48 h) measurements with activated charcoal canisters. The concentrations vary widely (30.2-315.4 Bq m(-3)) during the study period, and the overall mean is 170.3 +/- 39.6 Bq m(-3). The indoor radon concentration correlates negatively with both the outdoor temperature (R(2) = 0.06) and the wind speed (R(2) = 0.11) but positively with rainfall (R(2) = 0.03). The results showed that changes in meteorological parameters cause more variations in indoor radon concentrations than the differences in the buildings' characteristics (i.e., designs, materials, etc). However, these variations are not significant (at 1% significance level).

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Exposures to various components of the natural background radiation in Kenya were estimated using measured activity concentrations of natural radionuclides and conversion factors. Contributions to the total effective dose include: 0.1 to 2.0 mSv.y -1 from terrestrial gamma radiation; 0.2 to 0.7 mSv.y -1 and a per capita of 0.4 mSv.y -1 from cosmic radiation; and 0.4 to 6.0 mSv.y -1 from inhalation of radon ( 222 Rn). Radon concentrations also range from 5 to 1200 Bq.m -3 in indoor air and from 1 to 410 Bq.1 -1 in drinking water. Considering the population distribution in relation to living habits of the people and to the relief and the geology in Kenya, it is concluded that the average annual effective dose in Kenya is higher than the global average. Ingestion of volcanic ash by some people, particularly pregnant women, was also identified as an additional (unusual) internal exposure pathway.

Current-voltage () characteristics of Nandi flame seed cuticles (NFSCs) have been studied as a function of irradiation, annealing, and poling temperature. The cuticles showed memory and threshold switching. Threshold voltage was about 5 V which is almost five times higher than observed in synthetic polymers. The threshold voltage increased to 6–8 V after irradiation and annealing depending on the duration of annealing or irradiation. After switching, conductivity increased by an order of . In reverse bias, increase of current was observed and the memory hysteresis loop was at higher conductivity than at the time of switching. Switching effect was minimized at a poling temperature of 370 K. Formation of semiquinones and quinoid radicals from phenolic compounds may have contributed to electrical switching and hysteresis effect.