Analysis by Energy Dispersive X-Ray Fluorescence (ED-XRF) technique of liquid samples and specimens in aqueous media requires that the sample chamber be flushed with helium gas. Moreover the sample should also be covered with mylar foil to hold the sample. The helium environment and the X-ray beam but also affect the sensitivity of different elements. An investigation was carried out with six multielement NBS standards to evaluate the effect of helium environment and mylar foil on the sensitivity of various elements. The effect of both the factors can be employed to improve the results of liquid samples with ED-XRF technique.
Authors:R. Singh, R. Khatri, E. Pambid, and N. Abbas
A relatively less expensive Phillips PV 9500/SY 585 automatic energy dispersive X-ray fluorescence (EDXFR) spectrometer with rhodium target, was modified using a commercial kitchen aluminium wrapping foil filter, for the determination of chloride in bifunctional reforming catalysts. Quantitation of chloride was carried out by the Claisse-Quintin method with a catalyst sample of known chloride content as an external standard. The results of EDXRF chloride analysis of different catalyst samples, containing varying amounts of percent carbon and chloride, compared well (p>0.75) with those obtained by silver chloride precipitation method. The small values of percent relative standard deviations at 0.4 to 4.5% showed a good reproducibility of the method. With the total analysis time of a few minutes combined with no sample preparation, the present method seems to be superior as compared to presently employed methods of chloride analysis in reforming catalysts.
Authors:R. Kumar, G. Baheti, M. Chacharkar, and P. Khatri
The corrosion of aluminium has been studied employing the irradiation in situ by neutrons from252Cf and gamma radiations from60Co. The effects of irradiation indicated the absence of pitting, suppression of the corrosion rate, i. e., quantitative reduction in corrosion when measured as weight loss as compared with unirradiated specimens. A protective grayish layer had emerged on the specimen surface which was akin to that formed in simulated experimental conditions carried out in presence of hydrogen peroxide. The possible mechanisms of the elimination of pitting and formation of grayish layer on the surface are discussed.
Authors:T. Chapagain, B. Khatri, P. Bhattarai, B. Luitel, G. Ortiz-Ferrara, and R. Sharma
Intercropping potato with quality protein maize (QPM) could improve the livelihood and nutritional status of the resource-poor farmers who produce and consume them. A study was conducted from 2008 to 2010 to assess the performance of three improved potato varieties in an intercropping system with an improved QPM in the high hills of Nepal. The QPM was sown for four consecutive weeks following potato planting. The commercial potato varieties Janak Dev, Kufri Jyoti and Khumal Seto-1 were used, while the improved QPM was Poshilo Makai-1. Delayed intercropping caused a reduction in the maize yield, but an increase in the potato yield. The highest potato yield was obtained from maize intercropping after four weeks. The grain yield of maize was significantly reduced by late planting beyond the second week. The average weekly rate of increase due to maize intercropping was better for Janak Dev and Kufri Jyoti, while Khumal Seto-1 was less suitable for intercropping. The land equivalent ratio for potato-maize intercropping was 2.23. The results suggest that Poshilo Makai-1 could be incorporated in potato-maize intercropping, leading to higher returns and nutritional benefits. The findings underline the importance of variety and date of intercropping to maximize production. The findings have implications for harnessing higher productivity on resource-poor farms, and could contribute to food and nutritional security for resource-poor farmers.