A simple method for calibration of Lucas scintillation cell counting system for measurement of 226Ra and 222Rn

Known quantity of radium from high grade ore solution was chemically separated and carefully kept inside the cavity of a Lucas Cell (LC). The 222Rn gradually builds up and attain secular equilibrium with its parent 226Ra. This gives a steady count after a suitable buildup period (>25 days). This secondary source was used to calibrate the radon counting system. The method is validated in by comparison with identical measurement with AlphaGuard Aquakit. The radon counting system was used to evaluate dissolved radon in ground water sample by gross alpha counting in LC. Radon counting system measures the collected radon after a delay of >180 min by gross alpha counting. Simultaneous measurement also carried out by AlphaGuard Aquakit in identical condition. AlphaGuard measures dissolved radon from water sample by constant aeration in a closed circuit without giving any delay. Both the methods are matching with a correlation coefficient of >0.9. This validates the calibration of Lucas scintillation cell counting system by designed encapsulated source. This study provides an alternative for calibration in absence of costly Radon source available in the market. Keywords: Radon counting system, Calibration, Lucas cel

A review of radio chemical analysis and estimation of 210Po in soil matrices

The naturally occurring radionuclide 210Po, arising from the uranium–radium decay series, provides a considerable contribution to the radiation exposure to humans. Polonium is analyzed for a variety of purposes, including for radiological impact assessment or as a tracer of environmental processes. Losses of polonium may occur at temperatures above 100 °C, depending on conditions, requiring particular care in sample preparation and treatment. There has been little development regarding analysis of polonium in environmental samples since 1960 as radiochemical analysis of polonium is quite straight forward due to easy of source preparation through auto-deposition on to metal surfaces. In this paper a brief review of estimation of polonium in the soil samples have given emphasis

Molecular genetics and breeding of grain legume crops for the Semi-Arid Tropics

Grain legumes are important crops for providing key components in the diets of resource-poor people of the semi-arid tropic (SAT) regions of the world. Although there are several grain legume crops grown in SAT, the present chapter deals with three important legumes i.e. groundnut or peanut (Arachis hypogaea), chickpea (Cicer arietinum) and pigeonpea (Cajanus cajan). Production of these legume crops are challenged by serious abiotic stresses e.g. drought, salinity as well as several fungal, viral and nematode diseases. To tackle these constraints through molecular breeding, some efforts have been initiated to develop genomic resources e.g. molecular markers, molecular genetic maps, expressed sequence tags (ESTs), macro-/micro- arrays, bacterial artificial chromosomes (BACs), etc. These genomic resources together with recently developed genetic and genomics strategies e.g. functional molecular markers, linkage-disequilibrium (LD) based association mapping, functional and comparative genomics offer the possibility of accelerating molecular breeding for abiotic and biotic stress tolerances in the legume crops. However, low level of polymorphism present in the cultivated genepools of these legume crops, imprecise phenotyping of the germplasm and the higher costs of development and application of genomic tools are critical factors in utilizing genomics in breeding of these legume crops

Water quality under the changing climatic condition: a review of the Indian scenario

The current work reviews the state of Indian water quality under the climate change regime. Rising temperatures will lead to higher concentration of pollutants like nutrients (nitrates, phosphates etc.), persistent organic pollutants and pesticides. Probable negative consequences include increase in harmful algal blooms, toxicity hazards in people etc. Rising temperatures could lead to release of higher amounts of fluoride and uranium due to prevalence of drier oxic conditions, and also arsenic due to release from iron (hydr)oxides. Implications on emerging contaminants, a new class of pollutants without any regulatory status, is not clearly understood. Prevalence of microbes in water is also predicted to increase. Coastal aquifers appear to be at risk from salt water intrusion. Conflicts on the international and national platform is predicted to rise due to issues with sharing of water. Lastly, we also discuss the sustainability options for water in India under a changing climatic regime, under three broad subcategories signifying the roles of (1) science, (2) policies and legal framework and the (3) people perspective, while also highlighting the existing lacunae.by Nilotpal Das, Chandan Mahanta and Manish Kuma