NOPR Collection:

Effect of some Heterocyclic Synthetic Nitrogen Regulators for Increasing the Efficacy of Urea in Paddy-wheat Crop Rotation

2005-06-01T00:00:00Z

Title: Effect of some Heterocyclic Synthetic Nitrogen Regulators for Increasing the Efficacy of Urea in Paddy-wheat Crop Rotation Authors: Sharma, J P; Singh, Teekam; Taneja, H.K.; Tomar, S.S. Abstract: In developing countries urea is the major source of nitrogen, but it is a matter of concern that one-third of urea (30-35%) is only utilized by the plants and the rest two-third (65-70%) is lost by volatilization, denitrification, leaching and absorbed in lower profiles of the soil. Due to this farmers suffer a great economic loss and have to face the polluted environment and contaminated water. This wasteful loss of nitrogen can be controlled to a certain extent by application of some heterocyclic nitrogen regulators like pyrazoles and isoxazoles. The isoxazole regulators can control urea hydrolysis and denitrification, and increase N-uptake and apparent N-recovery by formation of nitrogen complexes in soil which can be easily adsorbed by growing plants. The present investigation was carried out in a IARI farm soil (Typic Haplustept) and urea fortified with different synthetic isoxazole compounds for N-regulation. The study indicated that the test regulators (at 5% of the fertilizer level) significantly retarded the nitrification of soil applied urea. In vitro studies have revealed that whereas 75% soil applied urea-N got converted to nitrate-N within a week's time, the use of test chemicals delayed the urea transformation for 10-14 days to achieve the same level of nitrate-N. These regulators not only increased the dry matter yield by 20-25% over control, but their application along with fertilizer also increased the apparent -N recovery by 20-40% in both paddy and wheat crops. The use of these chemicals was not detrimental to soil health. These nitrification regulators retarded the conversion of ammoniacal-N to nitrate-N without accumulation of nitrite-N, which is supposed to be toxic to the plants. Page(s): 98-101

Platoon Size and Headway for Indian Traffic Condition: A New Approach

2005-06-01T00:00:00Z

Title: Platoon Size and Headway for Indian Traffic Condition: A New Approach Authors: Kumar, Ravindra; Singh, Bhagwan; Jain, P K; Chaudhary, Sanjay Abstract: A microscopic study has been carried out to investigate the relationship between platoon size and headway of vehicle under mixed traffic condition on different road sections of Delhi. Since size of the platoon mainly depends on headway and traffic densities, so the statistical model has been developed to under understand easily about the minimum number of required vehicles for platoon formation and end process. This study helps to understand the various problems associated with Indian traffic and find the solution for uninterrupted and smooth traffic flow. Page(s): 91-97

Characterization of Hydrogenated Amorphous Silicon Thin Films by Infrared and EPR Spectroscopy

2005-06-01T00:00:00Z

Title: Characterization of Hydrogenated Amorphous Silicon Thin Films by Infrared and EPR Spectroscopy Authors: Arora, Manju; Gupta, S K Abstract: Hydrogenated amorphous silicon thin films grown by glow - discharge process were characterized by high resolution, non - destructive infrared (IR) and electron paramagnetic resonance (EPR) spectroscopic techniques to investigate different local arrangements formed in the film network like SiH , SiH₂ and (SiH₂)_n bonding groups, defects and microcrystalline silicon during growth. These groups and defects effect the conductivity and recombination process which plays important role in device fabrication. In this work, the vibrational bands pertaining to silicon and hydrogen bonded groups were tentatively assigned to reveal structural details of local bonding arrangements in amorphous and microcrstalline state. Infrared absorptance spectra were measured in the region 4000 - 400 cm^-1 at ambient and different low temperatures. In these spectra, absorption bands of SiH, SiH₂, (SiH₂)₂, (SiH₂)_n groups of amorphous hydrogenated silicon coexisted with microcrystalline silicon (mc -Si:H) stretching, bending, breathing, wagging and silicon transverse optic phonon vibrations. The appearance of microcrystalline silicon bands in these film spectra confirms its formation which starts growing due to the reaction of hydrogen radicals with unstable SiH₂ group present at the grain boundery. This chemical etching reaction is exothermic which breaks weak Si-Si and Si-H bonds and form strong Si-Si microcrystalline bonds and silicon particles through reorientational ordering of silicon hydrogen bonded groups in amorphous film network. Recently microcrystalline silicon find wide usage in optoelectronic devices and these investigations are very important in this context also. Electron paramagnetic resonance studies showed an isotropic single line spectrum due to formation of dangling bonds in amorphous hydrogenated silicon film. Page(s): 86-90

The Impedance Standards at National Physical Laboratory and Global MRA

2005-06-01T00:00:00Z

Title: The Impedance Standards at National Physical Laboratory and Global MRA Authors: Nath, Om Kar Abstract: The impedance standards section at the National Physical Laboratory has established primary standards of impedance and associated calibration facilities. These facilities are used to calibrate impedance standards and associated instruments available in echelon II level laboratories in India. As such measurement traceablity has been established at national level. International intercomparison of these standards is also done time-to-time with national laboratories of other countries; such as USSR, Germany, Countries of Asia Pasific region and South Africa etc. Thus National Physical Laboratory (India) has established impedance standards having traceability both at national and international level.
As such a well structured measurement system in the area of impedance standardization has been established, which provides a strong foundation for our country to enter in global market for international trade. The above mentioned impedance standards and associated facilities have been included in the BIPM global MRA. This would help to overcome rechnical barriers to trade (TBT) in global market and further strengthen the Indian economy in this area. Page(s): 81-85