On green-to-red line intensity ratio in the solar corona     

S. Chandra  U. Narain 《Solar physics》1976,46(1):183-184

An improved formula for the green-to-red line intensity ratio in the solar corona is proposed. The results are compared with those given by the previous expression.  相似文献   

Autoionization rate coefficients for some coronal ions     

H. P. Mital  U. Narain 《Solar physics》1977,54(2):387-391

Autoionization rate coefficients for some ions found in solar corona have been computed in the temperature range 10⁵–10⁸ K semiempirically. In each case the coefficients decrease as we go from less to more ionized ones and have a typical temperature dependence.  相似文献   

Histopathological Lesions in Heteropneustes fossilis Subjected to Acute Thiodan Toxicity     

A. S. Narain  B. B. Singh 《洁净——土壤、空气、水》1991,19(2):235-243

The common Indian freshwater catfish, Heteropneustes fossilis, was exposed to the 96 h-LC₅₀ (0.007-0.013 ppm) of the organochloride thiodan (endosulfan) for 4 days. The stressed fishes showed various histopathological changes. In the liver, extensive degeneration of cytoplasm, pycnosis of nuclei, and loss of glycogen was observed most commonly. Stasis of circulation and constriction of bile duct lumen was also seen frequently. In the kidney, shrinkage of glomeruli, cytoplasmic damage and epithelial desquamation in tubules, and extensive degeneration of hemopoietic stroma was commonly observed. In the intestine, the damage was comparatively negligible, the most common effect was an increased mucus cell activity leading to accumulation of mucoid exudates in the lumen.  相似文献   

Density perturbations in the earth's core due to hydromagnetic oscillations     

Rishi Narain Singh 《Pure and Applied Geophysics》1973,105(1):864-868

Summary The equation for density perturbation induced by plane hydromagnetic waves (responsible for geomagnetic secular variation) has been derived based on -plane formulation. It is deduced that for the usual physical properties of the earth's core such a density perturbation would be small and would not be, in the main, responsible for the recently discovered correlation between gravitation and geomagnetic potentials.  相似文献   

TransientEM screening in two concentric spherical shell model     

Rishi Narain Singh 《Pure and Applied Geophysics》1972,94(1):226-232

Summary Different results have been obtained by Negi and Wait in connection with the effect of overburden in electromagnetic exploration by assuming different definitions of screening factor. Both definitions are based on frequency domain considerations. We shall describe the screening characteristics for a transient field with a two-concentric shell model with screening factor=(magnetic field of target and screen-magnetic field of screen alone)/(field of target alone). It is found that the screening factor does become more than one in some situations which means that the EM response of target is more in some cases when the screen is present than when it is absent.Presented at the fifty-second Annual Meeting of AGU during April 12–16, 1971, Washington, D.C.  相似文献   

A matrix method for heat conduction in multi-layered media     

Janardan G. Negi  Rishi Narain Singh 《Pure and Applied Geophysics》1969,73(1):143-151

Summary A matrix formalism is developed to facilitate computation of temperature distribution in the steady state in the interior of a multi-layered earth. The idealized model consists of homogeneous and isotropic layers of constant (but arbitrary) values of heat production as well as thermal conductivities. The known surface data is continued by this method to define the thermal structure at any desired point of the interior for planar and spherical stratification. Extension of the problem to the unsteady flow conditions has been presented.  相似文献   

Comments on the continuous incipient intrusion mechanism     

Rish Narain Singh 《Pure and Applied Geophysics》1974,112(1):118-121

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A reinterpretation of the linear heat flow and heat production relationship for the exponential model of the heat production in the crust     

Rishi Narain Singh  Janardan G. Negi 《Geophysical Journal International》1979,57(3):741-744

Summary. The conventional assumption of the equality of the slope of the empirical linear heat flow/heat generation relation and the logarithmic decrement in the exponential model of the heat production is not valid. The rigorous analysis of the heat flow equation shows that, with the increase of the magnitude of the slope, the invalidity becomes significant. In the Indian shield region, the available estimate of the slope is 14.8 km, while the corresponding logarithmic decrement value is 17.2 km, However, it may be emphasized that in the step model the slope is rightly interpreted as the thickness of the radioactive layer.  相似文献   

Heat transfer in multi-layered media with temperature dependent sources     

Janardan G. Negi  Rishi Narain Singh 《Pure and Applied Geophysics》1968,69(1):110-118

Summary The paper describes a theoretical investigation of heat transfer in stratified horizontal slab and spherical shell containing temperature dependent heat sources. The desired expressions of temperatures contain only ordinary functions suitable for high speed computation. The results can find applications in defining the local and global temperature distributions in the earth's crust.  相似文献   

On some properties of coronal mass ejections in solar cycle 23     

Nishant Mittal  Udit Narain 《New Astronomy》2009,14(3):341-346

We have investigated some properties such as speed, apparent width, acceleration, latitude, mass and kinetic energy, etc. of all types of coronal mass ejections (CMEs) observed during the period 1996–2007 by SOHO/LASCO covering the solar cycle 23. The results are in satisfactory agreement with previous investigations.  相似文献