Demand Projections for Foodgrains in India

Demand for foodgrains has been estimated for India for the years 2011-12, 2016-17 and 2021-22, by accounting for the factors like urbanization, regional variations in consumption pattern, shifts in dietary pattern and income distribution, limit on energy requirement and changes in tastes and preferences of consumers for food varieties. Indirect demand including ‘home away demand’ has also been considered in working out these food demand projections. Policy scenario has been presented and yield targets for the years 2011-12, 2016-17 and 2021-22 have been projected to meet the demand of foodgrams in these years.Agricultural and Food Policy,

A two-coil mutual inductance technique to study matching effect in disordered NbN thin films

Although matching effects in superconducting anti-dot arrays have been studied extensively through magneto-resistance oscillations, these investigations have been restricted to a very narrow temperature window close to the superconducting transition. Here we report a "two coil" mutual inductance technique, which allows the study of this phenomenon deep in the superconducting state, through a direct measurement of the magnetic field variation of the shielding response. We demonstrate how this technique can be used to resolve outstanding issues on the origin of matching effects in superconducting thin films with periodic array of holes grown on anodized alumina membranes

Strengthening Pluralistic Agricultural Information Delivery Systems in India

The study on agricultural information flow has revealed that only 40 per cent farm households access information from one or the other source. The popular information sources among farmers have been reported to be fellow progressive farmers and input dealers, followed by mass media. The public extension system has been found to be accessed by only 5.7 per cent households. Only 4.8 per cent of the small farmers have access to public extension workers as compared to 12.4 per cent of large farmers. The sector-wise study on the type of information, sought has revealed that a majority of the farmers have sought information on seed (32-55%) in the cultivation sector; on health care (26-54 %) in animal husbandry; and on management and marketing (8-46 %) in fisheries. Regarding adoption of information by farmers, input dealers and other progressive farmers have depicted greater influence mainly due to easy and convenient access to these sources. The study has suggested promotion of farmers-led extension and strengthening of public extension services to improve coverage and efficiency of agricultural information delivery systems.Agricultural and Food Policy,

Conformational Study of Polyelectrolytes

We have presented the conformational study of anionic polyelectrolyte, sodium sulfonated polystyrene having molecular weight 70kDa with the variation of the added electrolyte concentration. From the zeta potential measurements we found the decrease in particle mobility on increasing the salt concentration from 0M to 0.15M resulting in a decrease in the effective charge on the molecules. A similar decreasing pattern was observed for the viscosity measured by capillary viscometer with increase in the electrolyte concentration. The hydrodynamic radius of the particles obtained from the dynamic light scattering experiments showed significantly lower values with increment in salt concentration. The decreasing values of these parameters with rise in ionic strength indicate the collapsing of the extended polyelectrolyte chains in presence of salt

Manufacture of urea

Urea is in many ways the most convenient form for fixed nitrogen. It has the highest nitrogen content available in a solid fertilizer (46 %). It is easy to produce as prills or granules and easily transported in bulk or bags with no explosive hazard. It leaves no salt residue after use on crops. Its specific gravity is 1.335, decomposes on boiling and is fairly soluble in water. The principal raw materials required for this purpose are NH3 & CO2.Two reactions are involved in the manufacture of urea. First, ammonium carbamate is formed under pressure by reaction between CO2 & NH3. CO2 + 2NH3 NH2COONH4 H= -37.4 Kcal This highly exothermic reaction is followed by an endothermic decomposition of the ammonium carbamate. NH2COONH4 NH2CONH2 + H2O H= + 6.3 Kcal Various processes for the manufacture of urea are: 1) Snamprogetti ammonia stripping process 2) Stamicarbon CO2 stripping process 3) Once through urea process 4) Mitsui Toatsu total recycle urea process We selected the Snamprogetti ammonia stripping process for the manufacture of urea. In this process ammonia & CO2 are compressed & fed to the reactor. The unconverted carbamate is stripped and recovered from the urea synthesis reactor effluent solution at reactor pressure, condensed to an aqueous solution in a steam producing high pressure condenser & recycled back to the reactor by gravity. Part of the liquid NH3 reactor feed, vapourized in a steam heated exchanger, is used as inert gas to decompose & strip ammonium carbamate in the steam heated high pressure stripper. Energy balance & material balance of the plant is done. The selected capacity of the plant is 4,50,000 tons/year of urea producing 62,500 kg/hr of urea with 98 % purity. Urea reactor & vacuum evaporator are designed. The volume of reactor is calculated & found to be 195 m3. The length & diameter of the reactor are 40 m & 2.5 m respectively. The evaporator used is of climbing-film long- tube type. Snamprogetti ammonia-stripping urea process is selected because it involves a high NH3 to CO2 ratio in the reactor, ensuring the high conversion of carbamate to urea. The highly efficient ammonia stripping operation drastically reduces the recycling of carbamate and the size of equipment in the carbamate decomposition . Snamprogetti technology differs from competitors in being based on the use of excess ammonia to avoid corrosion as well as promote the decomposition of unconverted carbamate into urea. Uses of Urea: • About 56 % of Urea manufactured is used in solid fertilizer. • About 31 % of Urea manufactured is used in liquid fertilizer. • Urea-formaldehyde resins have large use as a plywood adhesive. • Melamine-formaldehyde resins are used as dinnerware & for making extra hard surfaces