Browsing by Author "U.S. Ram"

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A simple phenomenological model for the lattice dynamics of anisotropic metals
(Società Italiana di Fisica, 1975) U.S. Ram; S.S. Kushwaha
The theoretical results on the phonon dispersion relations of cadmium, a highly anisotropic h.c.p. metal, are split into the ionic and the electronic parts. The elements of the dynamical matrix for the former contribution are obtained using the noncentral forces, whereas the lattice contribution is evaluated in a simple phenomenological way. The calculated results are in good agreement with the experimental ones. © 1975 Società Italiana di Fisica.
Effect of date and level of earthing and nitrogen on productivity and nutrient availability in soils of ratoon sugarcane (Saccharum officinarum)
(2011) C.M. Dev; R.K. Singh; Gaurav Mahajan; M.K. Yadav; U.S. Ram
A field experiment was carried out during the spring seasons of 2008-09 and 2009-10 at Varanasi, Uttar Pradesh to find out the exact time and the height of earthing up and optimum dose of nitrogen for getting higher productivity, monetary returns, and changes in the fertility status of soils for ratoon sugarcane (Saccharum officinarum L.) at Varanasi. Earthing up on 25th April up to 20 cm height with 210 kg N/ha gave the highest cane yield, net returns and B:C ratio.
Effect of seedlings age, cultivars and weed management on weed dynamics, nutrient removal and yield of rice (Oryza sativa) under system of rice intensification (SRI)
(Indian Council of Agricultural Research, 2015) U.N. Shukla; V.K. Srivastava; Smita Singh; U.S. Ram; A.K. Pandey
A field experiment was conducted to study the effect of age of seedlings, cultivars and weed management on weed dynamics, NPK removal and yield of rice (Oryza sativa L.) under SRI at Banaras Hindu University, Varanasi during 2010 and 2011 in split-plot design replicated thrice. The tender aged seedling (10 days) and hybrid rice cultivar PHB 71 had significantly marked potential to minimize the weed dynamics of grassy weeds (Echinochloa spp. and Cynodon dactylon), sedges (Fimbristylis miliacea and Cyperus spp.) and BLWs (Ammania baccifera and Ludwigia parviflora) significantly that resulted in marked reduction on total weed density, weed dry weight, weed index resulted in higher weed control efficiency over older seedling (15 days) of NDR 359. Four times cono-weeding at 10, 20, 30 and 40 DAT minimised grassy weeds over rest of the weeding treatments, but at par with pre and post-emergence application of pretilachlor + bispyribac-Na herbicides in respect of sedges and BLWs with total weed density that resulted in improving weed index due to higher weed control efficiency over 15 days old seedlings and other weed management treatment during both the years of study. Similarly, transplanting of younger seedlings (10 days) of PHB 71 produced significantly higher rice yield under 4 times cono-weeding closely followed by pre and post-emergence application of pretilachlor + bispyribac-Na. Significantly lower NPK removal by weeds at 45 DAT recorded with 10 days old seedling of PHB-71 under 4 times cono-weeding at 10, 20, 30 and 40 DAT (W4), though remained at par with pre and post-emergence application of pretilachlor + bispyribac-Na.
Growth of cadmium iodide polytypes by dislocation‐controlled phase transformation
(1974) U.S. Ram
A discussion is made of the growth phenomenon of cadmium iodide polytypes in context with existing theories. It is shown that the formation of polytypes occurs when structural transformations in the basic phases (2H, 4H) are brought about by an appropriate sequence of dislocations. The deduction of the polytypic structures on the theoretical basis corresponds to experimental findings of other workers. Possible mechanism of the phase transformation and the occurrence of Zhdanov numbers 1, 2, and 3 in the zig‐zag structural sequence of CdI2 polytypes are also explained. Copyright © 1974 WILEY‐VCH Verlag GmbH & Co. KGaA
Splitting of X‐Ray diffraction spots, streaking along [ho.1] rows and growth of polytypic crystals
(1974) U.S. Ram; M. Dubey; G. Singh
[No abstract available]
Structure and growth of an unusual silicon carbide polytype 147R
(1973) U.S. Ram; M. Dubey; G. Singh
Most of the SiC polytypes known uptil now are found to be based on either of the basic structure 6H, 15R or 4H. A new polytype 147R with structure [(3332)432]3 has been discovered which is based on 33iî instead of either of the basic structures. In addition a small region of the same crystal is found to be a high-period polytype (588R or 196H) and is based on 147R. The implication of these observations regarding the growth mechanism of polytypic crystals has been discussed. © 1973, Walter de Gruyter. All rights reserved.