Browsing by Author "S.N. Rai"

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Biology and chemical control of carmine spider mite, Tetranychus cinnabarinus (Boisd.) (acarina: tetranychidae) on Ashwagandha, Withania somnifera
(1996) S.N. Rai; J. Singh
The biology and chemical control of carmine spider mite, Tetranychus cinnabarinus were studied on a medicinal plant, Withania somnifera in the autumn season (September-October) of 1992. The life cycle of female comprised eight developmental stages, while male had six stages in their life span. Female survived for a longer period due to two extra stages (deutonymph and teliocrysalis) as compared to male. The sex ratio was 4 : 1 in laboratory culture. Further, some morphometric parameters were recorded and the female was found to be longer in size than the male. Field experiments were also conducted to study the efficacy of some insecticides/acaricides against the infestation of carmine spider mite on Ashwagandha. Triazophos (0.05%) was least effective and dicofol (0.03%) was found to be the best among all the tested chemicals.
Comparative efficacy of neem based and chemical pesticides for management of root-knot nematode in tomato
(2000) M.K. Tripathi; R.C. Pandey; S.N. Rai
An experiment was conducted during Rabi season (1995-96) in Insectory, Department of Entomology, CSAUA and T, Kanpur to evaluate the various neem based pesticides along with some commonly used chemical pesticides for the management of root-knot nematode (Meloidogyne incognita) in tomato crop. Nimbecidine was found to be most effective which produced maximum tomato yield (38.74 mt/ha) followed by Nimbosol (35.98 mt/ha), Achook (33.41 mt/ha) and Suneem (30.94 mt/ha). Among the chemical pesticides phorate produced highest yield (30.48 mt/ha), cypermethrin (28.02 mt/ha) and phosphamidon (24.83 mt/ha) against control (14.98 mt/ha). Number of galls formed in roots and tomato yield was negatively correlated (r = -0.9162).
Electrical resistivity tomography for groundwater exploration in a granitic terrain in NGRI campus
(2013) S.N. Rai; S. Thiagarajan; Dewashish Kumar; K.M. Dubey; P.K. Rai; A. Ramachandran; B. Nithya
Rapid growth of residential colonies around the campus of the CSIR-National Geophysical research Institute (NGRI), Hyderabad during the last two decades has resulted in either disappearance or drastic reduction in size of open space and ponds for groundwater recharging. Withdrawal of groundwater for domestic uses has increased several fold causing continuous lowering of the water table in and around the campus. Due to this changed scenario, availability of groundwater to meet the requirement of CSIR-NGRI is drastically reduced. This communication presents the results of electrical resistivity tomography (ERT) carried out in the CSIR-NGRI premises to locate potential groundwater resources as well as choose suitable sites for artificial recharging of aquifer. Groundwater potential zone identified by ERT is verified at one site by drilling a bore well.
Force constants of molecules with strongly coupled vibrations
(1970) S.N. Thakur; S.N. Rai
[No abstract available]
Hydatid disease in children may have an atypical presentation
(2000) A.N. Gangopadhyay; P. Sakti; S. Sahoo; P. Sharma; D.K. Gupta; C.K. Sinha; S.N. Rai
Although there is voluminous literature describing various aspects of hydatid disease in children, little attention has been paid to the small group of patients whose symptoms result in atypical presentation. This article addresses this problem, describing the features in ten children aged from 2 to 12 years. The sites of involvement were within a choledochal cyst (1). the pelvic cavity (1), the spleen (1), and transverse mesocolon. Albendazole was efficacious in the treatment of one recurrent case, as well as in preventing recurrence. © Springer-Verlag 2000.
Ionicity of the M-X bond in the tetrahalides of group IV elements
(1971) S.N. Rai; S.N. Thakur; D.K. Rai
The intramolecular force field for the tetrahalides of Group IV elements has been calculated using the extremal properties of the force constants and the results discussed in the light of the ionicity of the M-X bond. The stretching force constants fd are predicted for SnF4 and HfF4. © 1971.
Kinematical evaluation of force constants: Application to trihalides of phosphorus and arsenic
(1970) S.N. Rai; S.N. Thakur
The F-matrix elements for the two-dimensional symmetry species are dependent on one arbitrary parameter in addition to the vibrational frequencies. This parameter has been chosen as an angle π (0 ≤ π ≤ 2π) and the F-matrix elements for the A1- and the E-species of trihalides of phosphorus and arsenic have been studied as functions of π. It is found that the best values of the force constants obtained from Coriolis 1; constants can be correlated with those values of the angle ξ for which the bending force constant exhibits a minimum. © 1970 Australian Journal of Chemistry. All rights reserved.
Mean Amplitudes of Vibration for Tetrahedral Molecules and Ions
(1974) D.K. Sharma; A.N. Pandey; A.K. Dublish; S.N. Rai
Mean amplitudes of vibration for 38 tetrahalides and 15 tetraoxides have been computed at temperatures T = 0 °K, T= 298.15 °K and T=500 °K employing most recent vibralional data. Müller's method has been followed in solving the two dimensional Cyvin's secular determinant. The results have been briefly discussed. © 1974, Walter de Gruyter. All rights reserved.
Molecular force fields for some anions and molecules of MX6 type (X = Cl, Br)
(1971) S.N. Rai; S.N. Thakur; D.K. Rai
Force constants for six ions and one molecule, belonging to Oh point group, have been evaluated by using three different models for potential field. Validity of the methods has been discussed. Coriolis coupling constants, mean amplitudes of vibration and potential energy distribution for each mode have also been calculated. © 1971 Indian Academy of Sciences.
Neonatal Tuberculosis of the Spine
(1998) D.K. Gupta; S.C. Gopal; S.P. Sharma; A.N. Gangopadhyay; S.N. Rai
[No abstract available]
Normal Coordinate Analysis of Nitrogentrichloride
(1972) S.N. Rai; Badri Rai; K.P.R. Nair; S.N. Thakur
The intramolecular force fields of nitrogen trichloride have been determined using the recent experimental data on the vibrational frequencies. Three different methods have been used for the evaluation of force constants. The results obtained are quite consistent. © 1972, Walter de Gruyter. All rights reserved.
On the Application of OVFF to MX6 Type Ions
(1972) J.N. Rai; S.N. Tiwary; S.N. Rai
Force constants for nine ions belonging to Oh point group have been evaluated by using Orbital Valence Force Field. The constants have been compared with their values obtained by using Urey-Bradley Force Field. The validity of the two methods has been discussed. © 1972, Walter de Gruyter. All rights reserved.
On the variable-charge Coulomb-projected Born approximation
(Springer-Verlag, 1984) C.S. Singh; S.N. Rai; R. Srivastava; D.K. Rai
Total cross-sections for electron impact excitation of 11S - 23S transition in helium have been calculated using variable-charge Coulomb-projected Born approximation and also using a distorted wave model in which the prior form of the T-matrix is used. The comparison of the two sets of results enables us to make certain observations about the suitability of the variable-charge Coulomb-projected Born approximation. © 1984 Springer-Verlag.
Population dynamics and control of Aceria cajani on Pigeonpea in Varanasi
(1999) S.N. Rai; B.K. Singh; J. Singh
[No abstract available]
Population trend in Brevipalpus phoenicis on Ashwagandha in relation to weather factors in Varanasi
(1997) S.N. Rai; J. Singh
The population in Brevipalpus phoenicis (Geij.) on Ashwagandha, Withania somnifera Dunal. (medicinal plant) was observed from January to December during the years 1994 and 1995 at medicinal plants gardens in Varanasi. The population was seen throughout the year. The population started increasing from April and reached its peak during summer. Minimum population of mite was recorded in November in 1994 and in December in 1995.
Studies on life history and feeding behaviour of Cunaxa setirostris (Hermann)(Acarina:Cunaxidae under laboratory conditions)
(1997) S.N. Rai; Janardan Singh; M. Arbabi
The aim of present study is to record the cunaxid mites and to observe the developmental stages and feeding behaviour of Cunaxa setirostris (Hermann) on the most injurious mite (Tetranychus ludeni Zacker) of Varanasi region of eastern Uttar Pradesh. During the survey, five species of T. cunaxid mites were collected from twenty different plants. The female of C. setirostris completed its life cycle on T. ludeni within 27.5 ± 3.6 days comprised one larval and three nymphal stages. Whereas, the male attained maturity within 23.3 ± 2.1 days and had one larval and two nymphal stages. The maximum 87% prey consumption was recorded during the oviposition period (44.6 ± 12.8) days with an average fecundity of 132.4 ± 40.6 eggs. The total mortality during development period of this predator was 80% which included 48% larval mortality.
Studies on nutrient status of different vermicompost
(1999) Indrajeet; S.N. Rai; J. Singh
[No abstract available]
Use and consequent effects of the complex effective charge
(1986) C.S. Singh; S.N. Rai
A complex effective charge is used to calculate the first Born electron-impact cross sections of the hydrogen atom. The results are compared with experimental values, and the usefulness of employing an effective charge is discussed. © 1986 The American Physical Society.