Khem Singh

Assessment of Methane and Nitrous Oxide Emissions from Livestock in

Methane emission contribution from Indian livestock is the highest (>70%) as compared to various other subsectors from agriculture sector viz. rice cultivation and open burning of crop residue. Methane emission factor (MEF) for ruminant livestock has been developed and is based on the country specific activity data. Methane emission from Indian livestock is estimated as 9.92±2.37 Tg for the year 1994. Major emissions are from enteric fermentation (~90%) and are estimated to be around 8.97±2.22 Tg, while from manure management is only around 0.95±0.15 Tg. Nitrous oxide emissions from livestock is small and is estimated to be around 0.99 Gg in 1994. Methane emission was highest from cattle followed by buffalo and other species in livestock. Among the Indian states, Uttar Pradesh (UP) is the highest methane producer followed by Madhya Pradesh (MP), Bihar and Rajasthan due to their larger and denser livestock population. However the highest methane emission density per square kilometer is estimated for Punjab followed by West Bengal and Bihar. Methane emission from livestock had increased in last decades viz. from 9.0 Tg in 1981 to 9.9 Tg in 1992 mainly due to increase in animal population. It had stabilized thereafter mainly due to stabilization in animal population. India is deficient in livestock’s feed resources. Low milk productivity and high methane generation per kg milk in Indian livestock is due to animal’s feed having low quality roughage based diets with nutrient deficiency.

Evaluation of purity with its uncertainty value in high purity lead stick by conventional and electro-gravimetric methods

BackgroundA conventional gravimetry and electro-gravimetry study has been carried out for the precise and accurate purity determination of lead (Pb) in high purity lead stick and for preparation of reference standard. Reference materials are standards containing a known amount of an analyte and provide a reference value to determine unknown concentrations or to calibrate analytical instruments. A stock solution of approximate 2 kg has been prepared after dissolving approximate 2 g of Pb stick in 5% ultra pure nitric acid. From the stock solution five replicates of approximate 50 g have been taken for determination of purity by each method. The Pb has been determined as PbSO4 by conventional gravimetry, as PbO2 by electro gravimetry. The percentage purity of the metallic Pb was calculated accordingly from PbSO4 and PbO2.ResultsOn the basis of experimental observations it has been concluded that by conventional gravimetry and electro-gravimetry the purity of Pb was found to be 99.98 ± 0.24 and 99.97 ± 0.27 g/100 g and on the basis of Pb purity the concentration of reference standard solutions were found to be 1000.88 ± 2.44 and 1000.81 ± 2.68 mg kg-1 respectively with 95% confidence level (k = 2). The uncertainty evaluation has also been carried out in Pb determination following EURACHEM/GUM guidelines. The final analytical results quantifying uncertainty fulfills this requirement and gives a measure of the confidence level of the concerned laboratory.ConclusionsGravimetry is the most reliable technique in comparison to titremetry and instrumental method and the results of gravimetry are directly traceable to SI unit. Gravimetric analysis, if methods are followed carefully, provides for exceedingly precise analysis. In classical gravimetry the major uncertainties are due to repeatability but in electro-gravimetry several other factors also affect the final results.