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51.
52.
S. Gupta 《洁净——土壤、空气、水》1987,15(2):185-192
The fish Cyprinus carpio (HAM.) and Channa punctatus (BL.) of the size ranging between 6.0 ± 1.2 cm and 28.0 ± 1.6 cm were exposed to different concentrations of industrial effluents from M/s Punjab Tannery Ltd. (Jalandhar), M/s Spinning Mill Ltd. (Hoshiarpur) and M/s Food Specialist Ltd. (Moga) for evaluating the influence of fish size on the acute toxicity of these effluents. Results indicate that the relative toxicity of the effluents decreased with the increase in fish size from 6.0 ± 1.2 cm to 20.6 ± 1.5 cm. However, for specimens of the size of 28.0 ± 1.6 cm and more, the toxicity of the effluents increased with an increase in fish size. On the basis of the relative toxicity to fish, effluent from Punjab Tannery was found highly toxic and from Food Specialist Industry, the least toxic. 相似文献
53.
The relative toxicities of seven non insecticidal chemicals to Mesocyclops leuckarti were tested. The relative toxicity of each chemical is given as under: Chlorine water > Potassium permanganate > Cetavlon > Quicklime > Common alum > Savlon > Sodium bicarbonate. 相似文献
54.
M. C. Gupta V. P. Krishnarajan Shailesh Nayak 《Journal of the Indian Society of Remote Sensing》2001,29(1-2):79-83
Aquaculture has emerged as one of the fast growing industries in the developing countries both for domestic consumption as well as for the export. This industry not only generates foreign exchange to the country but also provides employment opportunities to the skilled and unskilled rural poor. On the other hand, aquaculture has also some negative impacts on the environment which are mainly due to conversion of mangroves and agricultural, salination of surface water resources and agricultural land at some places besides causing pollution and diseases. All the major shrimp farming countries of the world have faced environmental problem due to intensification, improper and uncontrolled planning by greed and unlimited profit motives of a section of aquaculture community. In view of this, a proper environmental management is a basic need to sustain the industry in the long run. Selection of a suitable site in the coastal areas is the first and the foremost step which is a crucial factor in determining the success of shrimp farming. The present paper discusses the selection of brackish water aquaculture sites using remote sensing satellite data and GIS on the Cannanore coast. Different aquaculture sites in the area were evaluated using a GIS package. Finally a prioritization map showing the sites in the descending order of their priority was generated. 相似文献
55.
Summary The eye readings of easterly declination at Trevandrum observatory have been analysed to determine solar and lunar daily vatiations. Hourly readings during February 1853 to February 1865 are analysed by Chapman-Miller method. The 8 values read at unequidistant day-time hours during March 1865 to December 1869 are analysed to compute the amplitude and phase of the semimonthly wave at each of the hours separately. The semi-monthly lunar wave obtained from the hourly readings shows a considerable night-time variation. A brief discussion of the results is also given.Contributions from the Earth Physics Branch, No. 323 相似文献
56.
Sushil Chandra Das Gupta 《Pure and Applied Geophysics》1954,27(1):1-6
Summary Displacements and stresses produced by impulsive radial pressure and by impulsive twists have been determined. In the former case total flow of energy across a spherical boundary has been obtained. 相似文献
57.
The effects of E-region electric fields on F-region parameters like height of constant electron density contours (hN) and semi-thickness, at an equatorial station, Trivandrum, are investigated. The E-region east-west electric field (Ey) has been deduced using the horizontal magnetic field values from the ground magnetograms. It is found that the semi-thickness parameter and hN follow closely the E-region electric field (Ey) variations in the forenoon and noon periods. In the afternoon, it is shown that there is close association between hN and Ey, when the electric field variations are large. On a day-to-day basis also, hN and the E-region electric field show very good correlation in the forenoon and noon hours. It is also shown that higher levels are affected more than the lower levels in the F-region by Ey. 相似文献
58.
S. R. Das Gupta 《Astrophysics and Space Science》1974,30(2):327-342
Chandrasekhar'sH-functionH(z) corresponding to the dispersion functionT(z)=|
rs
–frs(z)|, where [f
rs
(z)] is of rank 1, is obtained in terms of a Cauchy integral whose density functionQ(x,
1,
2,...) can be approximated by approximating polynomials (uniformly converging toQ(x)) having their coefficients expressed as known functions of the parameters
r
's. A closed form approximation ofH(z) to a sufficiently high degree of accuracy is then readily available by term by term integration. 相似文献
59.
60.
G P Gupta 《Journal of Earth System Science》1978,87(11):231-234
The ionospheric absorption data measured by the sweep frequency method have been compared with the solar x-ray data in the band of 1–8 Å during quiet- and disturbed-sun conditions. The degree of solar x-ray control of the ionospheric absorption and the corresponding limit of solar x-ray flux have been discussed. 相似文献