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Analysis of soil redistribution patterns in watershed areas provides information for understanding soil erosion and deposition for implementing management practices to improve agricultural land conditions and reduce sediment loads in river systems. This paper has demonstrated the use of Cesium-137 (137 Cs) in estimating retrospective medium-term soil erosion rates in selected cassava cultivated areas in Pilar, a sub-watershed within the Inabanga watershed. To estimate erosion and deposition rates and elucidate the factors affecting the soil redistribution, samples were collected from a total of ninety-eight grid intersections representative of the local land use and slope gradients in the presence or absence of soil conservation practices. A proportional model was used to deduce soil redistribution rate estimates from 137 Cs inventories measured from individual soil samples. Soil measurements of 137 Cs activity-generated soil erosion rate gave values of 13.15 t ha-1 year-1 in cultivated areas practicing conservation measures and 22.23 t ha-1 year-1 in those with typical upland plantation, with the former corresponding to slight erosion case and the latter to moderate erosion case. The obtained values have provided an overview of the pattern of soil redistribution in the watershed area and reflect the impact of strategic soil erosion management being applied. Interestingly, in light of recent severe meteorological events befalling the region, e.g., super typhoon Haiyan and the 7.3 magnitude earthquake, the data obtained may serve as benchmark values for 137 Cs activities against which changes in the soil movement and soil redistribution pattern along the watershed areas can be evaluated.

Rectifier columns are considered to be a critical component in petroleum refineries and petrochemical processing installations as they are able to affect the overall performance of these facilities. It is deemed necessary to monitor the operational conditions of such vessels to optimize processes and prevent anomalies which could pose undesired consequences on product quality that might lead to huge financial losses. A rectifier column was subjected to gamma scanning using a 10-mCi Co-60 source and a 2-inch-long detector in tandem. Several scans were performed to gather information on the operating conditions of the column under different sets of operating parameters. The scan profiles revealed unexpected decreases in the radiation intensity at vapour levels between trays 2 and 3, and between trays 4 and 5. Flooding also occurred during several scans which could be attributed to parametric settings.