Browsing by Author "O.N. Singh"

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Dispersion characteristics of a helically cladded step-index optical fiber: An analytical study
(1995) U.N. Singh; O.N. Singh; P. Khastgir; K.K. Dey
A new type of step-index optical fiber, the helically cladded fiber (HCF), in which a conducting sheath helix is introduced at the core-cladding interface boundary, is proposed. By application of the appropriate sheathhelix boundary condition at the core-cladding interface, the modal characteristic equation is determined. The dispersion curves are also obtained. Analysis of the modal characteristic equation and dispersion curves reveals that only hybrid modes are supported, and the lowest-order mode is HE01. The pitch angle of the helix has no effect on the cutoff condition. Its effect is more pronounced in the case of the first odd modes. One retrieves the modal characteristics of the step-index fiber by setting the pitch angle equal to zero. Further, a fact of technical importance emerges: that the HCF behaves as a monomode guide for a comparatively large core radius. © 1995 Optical Society of America.
Effect of integrated nutrient management on growth, yield, nutrient uptake and ecnomics of french bean (Phaseolus vulgaris)
(2009) Rajput Pankaj Kumar; O.N. Singh; Yogeshwar Singh; Sachchidanand Dwivedi; J.P. Singh
An experiment was conducted during winter (rabi) 2004-05 and 2005-06 at Varanasi to study the effect of organic, inorganic and biofertilizers on french bean (Phaseolus vulgaris L.). The soil was sandy loam with pH 7.42. It was moderately fertile, being low in organic carbon, nitrogen, sulphur and zinc and medium in phosphorus, potassium and iron. The experiment was conducted in split-plot design with 3 replications. Five fertility levels combining inorganic (NPK) and organic (vermicompost) were allotted to main plot and 7 different combinations of biofertilzers (Rhizobium + Bacillus polymyxa + Pseudomonas fluorescence) and micronutrients (Zn and Fe) were subjected to sub-plot. Results showed superimposition of 25% N organic (recommended dose of N through vermicompost) to 100% NPK (recommended dose of NPK through fertilizers), being at par with 100% NPK + 50% N organic resulted in significant improvement in growth character, plant height, branches/plant, trifoliate leaves/plant and dry matter/plant, yield attributes (pod length, pods/plant and grains/pod), yield (grain and straw, harvest index) and nutrient (N, P, K, S, Zn and Fe) uptake. However, unfilled pods/pant was lesser with this fertility level. Gross and net returns were higher with 100% NPK + 50% N organic fertility level but B:C ratio was higher under 100% NPK + 25% N organic level. The combined effect of biofertilizers and micronutrients (biofertilizer + Zn + Fe treatment) was significantly better than their individual effects as this treatment significantly improved growth characters, yield attributes, yield, harvest index, nutrient uptake and B:C ratio. Furthermore, integration of 100% NPK +25% N organic and biofertilizer + Zn + Fe was conducive for getting significantly optimum yield.
Effect of Rates of Nitrogen and Varieties on Nitrogen-Use in Dwarf Wheat
(1979) O.N. Singh; Mahatim Singh
Nitrogen-use in dwarf wheat was studied in a field experiment during winter 1970-71 and 1971-72. N uptake was linear upto the highest rate of (200 kg N/ha) application. Nevertheless, 160 kg N/ha was conducive to top grain yield as the per cent N translocated to grain increased upto this point. Higher translocation of plant nitrogen to grain in H.D. 1941 and more nitrogen arrested in the straw of Kalyan Sona indicate the former be a better performer even under high fertility conditions. The senior author is thankful to the Indian Council of Agricultural Research for the award of senior research fellowship during the course of investigation. © 1979, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.
Effect of Rates of Nitrogen and Varieties on Yield and Its Contributing Characters in Dwarf Wheat
(1976) Mahatim Singh; O.N. Singh
A comparative account of yield and its contributing characters of dwarf wheat varieties Kalyan Sona, U.P. 301 and H.D. 1941 as affected, by the rates of nitrogen application was worked out in a field experiment during the winter seasons of 1970∼71 and 1971∼72 at the Research Farm of the Department of Agronomy, Banaras Hindu University. © 1976, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.
Efficacy of herbicides and nutrient management on weed dynamics and yield of French bean (Phaseolus vulgaris)
(Indian Council of Agricultural Research, 2018) Smita Singh; R.P. Singh; U.N. Shukla; J.K. Singh; O.N. Singh
A field experiment was conducted to assess the effect of herbicides and integrated nutrient managements on weed dynamics, NPK removal and yield of French bean (Phaseolus vulgaris L.) at Banaras Hindu University, Varanasi during 2009 and 2010. The results revealed that the pendimethalin fb quizalofop-p-ethyl had significantly marked potential to minimize the weed dynamics of Chenopodium album, Melilotus alba, Melilotus indica and Cyperus rotundus significantly, resulted in marked reduction on total weed density (41.48 and 41.11 nos/m), weed dry weight (45.62 and 44.68 g/m) and weed index at all stages of crop growth during 2009 and 2010, respectively and showed higher weed control efficiency over the alone application of pendimethalin. Recommended dose + 200 kg Wellgro Soil (Dust) minimized broad leaves weeds (BLWs) over rest of the fertility levels but at par with RD + 300 kg Wellgro Soil (Dust) in respect of BLWs weed density that resulted in enhanced weed index due to higher weed control efficiency over rest of the fertility levels during both the years of study. Significantly lower NPK removal by weeds at harvest recorded with pendimethalin fb quizalofop-p-ethyl under recommended dose + 200 kg Wellgro Soil (Dust), though remained at par with recommended dose + 300 kg Wellgro Soil (Dust). © 2018 Indian Council of Agricultural Research. All rights reserved.
From QTL to variety-harnessing the benefits of QTLs for drought, flood and salt tolerance in mega rice varieties of India through a multi-institutional network
(Elsevier Ireland Ltd, 2015) Renu Singh; Yashi Singh; Suchit Xalaxo; S. Verulkar; Neera Yadav; Shweta Singh; Nisha Singh; K.S.N. Prasad; K. Kondayya; P.V. Ramana Rao; M. Girija Rani; T. Anuradha; Y. Suraynarayana; P.C. Sharma; S.L. Krishnamurthy; S.K. Sharma; J.L. Dwivedi; A.K. Singh; P.K. Singh; Nilanjay; N.K. Singh; Rajesh Kumar; S.K. Chetia; T. Ahmad; M. Rai; P. Perraju; Anita Pande; D.N. Singh; N.P. Mandal; J.N. Reddy; O.N. Singh; J.L. Katara; B. Marandi; P. Swain; R.K. Sarkar; D.P. Singh; T. Mohapatra; G. Padmawathi; T. Ram; R.M. Kathiresan; K. Paramsivam; S. Nadarajan; S. Thirumeni; M. Nagarajan; A.K. Singh; Prashant Vikram; Arvind Kumar; E. Septiningshih; U.S. Singh; A.M. Ismail; D. Mackill; Nagendra K. Singh
Rice is a staple cereal of India cultivated in about 43.5Mha area but with relatively low average productivity. Abiotic factors like drought, flood and salinity affect rice production adversely in more than 50% of this area. Breeding rice varieties with inbuilt tolerance to these stresses offers an economically viable and sustainable option to improve rice productivity. Availability of high quality reference genome sequence of rice, knowledge of exact position of genes/QTLs governing tolerance to abiotic stresses and availability of DNA markers linked to these traits has opened up opportunities for breeders to transfer the favorable alleles into widely grown rice varieties through marker-assisted backcross breeding (MABB). A large multi-institutional project, "From QTL to variety: marker-assisted breeding of abiotic stress tolerant rice varieties with major QTLs for drought, submergence and salt tolerance" was initiated in 2010 with funding support from Department of Biotechnology, Government of India, in collaboration with International Rice Research Institute, Philippines. The main focus of this project is to improve rice productivity in the fragile ecosystems of eastern, northeastern and southern part of the country, which bear the brunt of one or the other abiotic stresses frequently. Seven consistent QTLs for grain yield under drought, namely, qDTY1.1, qDTY2.1, qDTY2.2, qDTY3.1, qDTY3.2, qDTY9.1 and qDTY12.1 are being transferred into submergence tolerant versions of three high yielding mega rice varieties, Swarna-Sub1, Samba Mahsuri-Sub1 and IR 64-Sub1. To address the problem of complete submergence due to flash floods in the major river basins, the Sub1 gene is being transferred into ten highly popular locally adapted rice varieties namely, ADT 39, ADT 46, Bahadur, HUR 105, MTU 1075, Pooja, Pratikshya, Rajendra Mahsuri, Ranjit, and Sarjoo 52. Further, to address the problem of soil salinity, Saltol, a major QTL for salt tolerance is being transferred into seven popular locally adapted rice varieties, namely, ADT 45, CR 1009, Gayatri, MTU 1010, PR 114, Pusa 44 and Sarjoo 52. Genotypic background selection is being done after BC2F2 stage using an in-house designed 50K SNP chip on a set of twenty lines for each combination, identified with phenotypic similarity in the field to the recipient parent. Near-isogenic lines with more than 90% similarity to the recipient parent are now in advanced generation field trials. These climate smart varieties are expected to improve rice productivity in the adverse ecologies and contribute to the farmer's livelihood. © 2015 Elsevier Ireland Ltd.
Genetic gain for rice yield in rainfed environments in India
(Elsevier B.V., 2021) Arvind Kumar; Anitha Raman; Shailesh Yadav; S.B. Verulkar; N.P. Mandal; O.N. Singh; P. Swain; T. Ram; Jyothi Badri; J.L. Dwivedi; S.P. Das; S.K. Singh; S.P. Singh; Santosh Kumar; Abhinav Jain; R. Chandrababu; S. Robin; H.E. Shashidhar; S. Hittalmani; P. Satyanarayana; Challa Venkateshwarlu; Janaki Ramayya; Shilpa Naik; Swati Nayak; Manzoor H. Dar; S.M. Hossain; Amelia Henry; H.P. Piepho
The complexity of genotype × environment interactions under drought reduces heritability, which determines the effectiveness of selection for drought tolerance and development of drought tolerant varieties. Genetic progress measured through changes in yield performance over time is important in determining the efficiency of breeding programmes in which test cultivars are replaced each year on the assumption that the new cultivars will surpass the older cultivars. The goal of our study was to determine the annual rate of genetic gain for rice grain yield in a drought-prone rainfed system in a series of multi-environment trials conducted from 2005 to 2014 under the Drought Breeding Network of Indian sites in collaboration with the International Rice Research Institute (IRRI). Our results show a positive trend in grain yield with an annual genetic yield increase of about 0.68 % under irrigated control, 0.87 % under moderate reproductive stage drought stress and 1.9 % under severe reproductive stage drought stress due to breeding efforts. The study also demonstrates the effectiveness of direct selection for grain yield under both irrigated control as well as managed drought stress screening to improve yield in typical rainfed systems. IRRI's drought breeding programme has exhibited a significant positive trend in genetic gain for grain yield over the years under both drought stress as well as favorable irrigated control conditions. Several drought tolerant varieties released from the programme have outperformed the currently grown varieties under varied conditions in the rainfed environments on farmers’ fields. © 2020 The Authors
Lattice dynamics of cobalt
(Società Italiana di Fisica, 1974) O.N. Singh; S.S. Kushwaha
The effective interaction within the metal consists of radial, tangential and electronic contributions. The electron gas screens out the individual ion. The screened Coulomb potential between the ions is used to account for the electronic contribution. The phonon dispersion relations and (θ-T)-curves for cobalt have been plotted and compared with available experimental results on the specific heat. © 1974 Società Italiana di Fisica.
Modal cutoff behavior of an optical waveguide with a multiloop core cross section embedded in a common cladding
(John Wiley & Sons Inc, 1998) A. Sharma; P. Khastgir; O.N. Singh
In this paper, a multiloop curve with a rather simple mathematical description in polar coordinates is chosen to describe the core cross-section boundary of a waveguide. This waveguide is used as a model representing a waveguide in which several cores are embedded in a common cladding. The cutoff equation for the lowest order modes is derived using the scalar wave approximation. Numerical computations are made to determine how the cutoff condition is modified as one increases the number of cores (loops) from three to ten. It is found that a waveguide with a cross section having fewer loops sustains more modes than that with a greater number of loops.
Polarised raman and infrared spectra and vibrational analysis for α-naphthylamine
(Springer India, 1985) R. Shanker; R.A. Yadav; I.S. Singh; O.N. Singh
The Raman spectrum of polycrystalline α-naphthylamine was recorded in the region 100-4000 cm-1. Polarisation measurements were made in CS2 and CHCl3 solutions. The infrared spectrum was recorded in nujol mull in the region 200-4000 cm-1. The resolution was better than 2 cm-1 and the accuracy of the measurements was within ± 2 cm-1 for all the spectra. Vibrational assignments have been proposed for the observed frequencies. Out of the 54 normal modes of vibrations, 51 modes could be observed experimentally. © 1985 Indian Academy of Sciences.
POLARIZED RAMAN & INFRARED SPECTRA OF 2-CHLORO-6-METHYLANILINE.
(1985) R. Shanker; R.A. Yadav; I.S. Singh; O.N. Singh
The polarized Raman spectra of 2-chloro-6-methylaniline have been recorded in the region 100-4000 cm** minus **1 in liquid phase on a Jobin Yvon Ramanor HG. 2S spectrometer equipped with an argon-ion laser source. The infrared spectrum of this compound has been recorded in the region 300-4000 cm** minus **1 in liquid phase on a Perkin Elmer-621 spectrometer using a cell with KBr windows. The observed bands have been assigned assuming C//s point group symmetry for the molecule and it has been possible to assign all the 45 normal modes of vibration in the present case.
Root growth, crop productivity, nutrient uptake and economics of dwarf pea (Pisum sativum) as influenced by integrated nutrient management
(Indian Council of Agricultural Research, 2014) Anupma Kumari; O.N. Singh; Rakesh Kumar
A field experiment was conducted during the two consecutive rabi seasons of 2007-08 and 2008-09 at Varanasi on sandy loam soil to study the effect of organic, inorganic and biofertilizers on dwarf pea (Pisum sativum L.). The experiment was conducted in a split-plot design and replicated thrice. All the fertility levels, viz. chemical fertilizers, vermicompost and control were allotted to main plot and combinations of biofertilizers (Rizobium+Bacillus polymixa +Pseudomonas fluorescence) and Zn along with control were subjected to sub-plot. Results showed superimposition of 50% Norganic (recommended dose of N through vermicompost) to 100% NPK (recommended dose of NPK through chemical fertilizers) resulted in significant improvement of dry matter/plant, yield (grain and straw, harvest index), root growth (root dry weight, root N content and cation exchange capacity of root) and nutrient uptake (NPKS and Zn). However nodulation (root nodules/plant, dry weight of nodules/plant and nitrogenase activity at 30 and 60 DAS) was lesser with this fertility level but significantly higher than 100% NPK and control (no application).Gross and net returns (R 45 358 and 31 223/ha) were noted higher with 100% NPK + 50% Norganic fertility level. Benefit: cost ratio (2.21) was also recorded higher with 100% NPK + 50% Norganic level. The integrated application of biofertilizers and Zn was recorded significantly better than control as this treatment lucidly improved dry matter, yield, harvest index, root growth, nodulation and nutrient uptake. Benefit: cost ratio was also higher with combined application of PSB and Zn. Furthermore, integration of 100% NPK + 50% Norganic and biofertilizers + Zn was conducive for getting significantly optimum yield (1873 kg/ha).
Theory of the vibrational spectra of transition h.c.p. metals
(Kluwer Academic Publishers, 1989) S.S. Kushwaha; O.N. Singh; S.K. Srivastava; N.B. Trivedi
A semi-first principle (SFM) model using the concept of a rigid-shell moving relative to its nucleus to simulate the response of the d-electrons has been proposed for studying lattice dynamics of transition metals which belong to the h.c.p. structure. The long-range interaction between ion-ion as well as shell-shell via conduction electrons is described using the screened potential and the short-range interaction is described using two-body and three-body unpaired forces between cores as well as shells. Elastic constants, phonon dispersion curves and thermal properties, e.g. lattice specific heat, Debye characteristic temperature of three prominent transition metals (Zr, Hf, Ti) have been calculated and compared with the experimental results. © 1989 Società Italiana di Fisica.
Unattenuated global modes in a planar dielectric waveguide with a flare in the direction of propagation
(John Wiley & Sons Inc, 1998) D.B. Singh; P. Khastgir; U.K. Singh; O.N. Singh
In this paper, continuing our earlier work on the modal properties of a planar waveguide with a flare, we examine whether unattenuated guided modes can exist in such waveguides. We use the scalar wave approximation and the cylindrical polar coordinates (ρ, φ, z) in a new way. Ordinarily, the guiding region lies between two distinct values of ρ, and the propagation is along the z-axis. In our case, however, we take the propagation in the ρ-direction, and the guiding region is bounded by two planes corresponding to two slightly different values of φ. This represents a planar waveguide with a flare, and we obtain the modal characteristic equation for unattenuated modes. Numerical computation shows the surprising result that global unattenuated modes can be sustained in such a structure for ν = 0, where ν is the modal index corresponding to the φ-coordinate.
Vibrational spectra, thermodynamic functions and barriers to internal rotation for isomeric trifluoromethylbenzoyl chlorides
(1992) R. Shanker; R.A. Yadav; I.S. Singh; O.N. Singh
The polarized Raman spectra (50–4000 cm−1) and IR spectra (180–4000 cm−1) of o‐, m‐ and p‐ trifluoromethylbenzoyl chlorides were recorded and all the 45 (30a′ + 15a") normal modes of vibration were assigned assuming Cs symmetry. Consistent assignments for the internal modes of the COCl and CF3 groups are proposed. Thermodynamic functions were computed and barriers to internal rotations for the COCl and CF3 tops were determined, using the assigned vibrational frequencies and assumed structural parameters for the three isomers. Copyright © 1992 John Wiley & Sons, Ltd.