Browsing by Author "Appiah, P."
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Item Assessment of Nuclear Moisture Density Gauges at a Secondary Standard Dosimetry Laboratory in Ghana during December 2015–December 2017(Iranian Journal of Medical Physics, 2020-01) Owusu-Banahene, J.; Appiah, P.; Adjei, D.N.; Gbekor, B.D.; Amoah, P.A.; Owusu-Manteaw, P.; Amoako, J.K.; Darko, E.O.; Asiedu, G.O.Introduction: Nuclear moisture density gauges are widely used in construction industry in different countries across the world, including Ghana, on a large scale. Like all irradiating devices, the nuclear gauges should be subjected to radiation safety assessment based on radiation protection and safety principles. Regarding this, the objective of this research was to investigate the radiation safety of the nuclear moisture density gauges to ensure the absence of any leakages from the radioactive source. Material and Methods: For the purpose of the study, a survey meter (RADOS-120) was used to measure and record the radiation dose once at a distance of 1 m from the surfaces of all sides of the nuclear moisture density gauge and very close distance from the surfaces of the device. Moreover, the device was examined using radiation contamination test and counts on a standard block. Results: A total of nine nuclear moisture density gauges manufactured by Troxler Electronics Inc. in the USA were evaluated within a period of 3 years. The minimum and maximum average dose rates were 0.49 and 66.67 μSv/h, respectively. The highest and lowest average dose rates were recorded in 2017 and 2016 on the devices with serial numbers of 38260 and 32839, respectively. Conclusion: The assessment of the nuclear moisture density gauges under study revealed no radiation contamination leakage. Furthermore, all the evaluated gauges were shown to function properly and were safe for the intended purposesItem Bio-Efficacy of Some Indigenous Ghanaian Botanical against the Almond Meal Moth: Ephestia Cautella (Walker)(University Of Ghana, 2015-07) Appiah, P.Ephestia cautella is one of the most important stored product insect pests found in granaries. Its activities tend to reduce germination and nutritive capacity of the infested seed and grains. The increasing rate of pest resistance, high cost and health risk in the use of insecticides to control insect pest have become issue of public concern. Therefore the use of botanical has been found to be very effective against stored product insect pests. Several plant products (leaves, oil, ash, seed extracts, and roots) are processed and mixed with stored products or applied as insecticides to control these pests. These are considered to be cheap, easily biodegradable and readily available for stored product protection. In this research, the bio-efficacies of Moringa oleifera, Ocimum canum, Securidaca longepedunculata and Zanthoxylum xanthoxyloides as bio-insecticidal agents against E. cautella were investigated. The powders of M. oleifera, O.canum, S. longepedunculata and Z. xanthoxyloides leaves were screened in the laboratory against the adults E. Cautella in the proportion of 50% and 100% wt/wt for all the botanicals. These showed the various bioactivities against the insects with 100% wt/wt treatments of Zanthoxlum xanthoxyloides proving to be most effective, as it significantly reduced the survival (90%) of the insects. The effect of petroleum ether extracts of the botanicals at different concentration (0.1g/mL, 0.3g/mL and 0.5g/mL) on the adult insect by grain treatment, effects on immature stages, effects on adult emergence in treated grains repellency, damage to the grains and germination tests were determined in the laboratory. The study showed that, the ability of the petroleum ether extracts to cause mortality was dosage dependent since mortality increased with higher concentration of the extracts. Significantly (p=0.005) lower number of eggs were laid on the treated grains compared with the untreated control. The botanicals had a tremendous effect on the adult emergence of E. cautella. There was no adult emergency at the highest concentration (0.5g/ml) for Moringa oleifera. There were significant differences in the number of adults University of Ghana http://ugspace.ug.edu.gh xiv emergence between the various treatments and the control. Overall percentage weight loss was lower (0.0-6.80%) in the botanical treatments than that of the untreated control (9.4-31.51%). Grains treated with botanicals gave an appreciable reduction in weight loss as compared with the control. Studies on the effects of the botanical on seed viability revealed that the botanicals did not hamper seed viability after 60 days storage period. The untreated control had the least percentage germination (25.0-25.3%). There was significant repellence of the insect by the different concentrations of the plant extracts. These results indicate that good protection of maize seed can be offered by indigenous Ghanaians botanicals acting as both repellents and anifeedants against Ephestia Cautella.