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31.
Jayant V. Narlikar 《Journal of Astrophysics and Astronomy》1997,18(4):353-362
This paper summarises the recent work on the quasi-steady state cosmology. This includes, the theoretical formulation and
simple exact solutions of the basic equations, their relationship to observations, the stability of solutions and the toy
model for understanding the growth of structures in the universe. 相似文献
32.
33.
The calculation of stresses induced inside the soil mass by the foundation loads forms an essential step in most of the geotechnical engineering problems dealing with the probable behaviour of foundations. The distribution of stresses on horizontal planes containing reinforcements at various depths is required in the analysis and design of reinforced soil foundations. An accurate evaluation of contact pressure distribution at the interface is a prerequisite for the computation of stresses inside the soil mass. Of the several approaches the elastic-plastic approach of computing the contact pressure distribution appears to be reasonable. Using this approach non-dimensional equations have been derived for calculating the contact pressure distribution beneath rigid circular foundations on sands. The contact pressure distribution so derived has been used for computing the stresses at various points using elastic theory. The results have been graphically presented and are compared with Boussinesq's distribution for uniform contact pressure. 相似文献
34.
Mangalore, one of the fastest growing cities along the west coast of India has witnessed a leap in industrialisation and urbanisation during the last decade. This study focuses on the quality of the groundwater of Mangalore city. The results are compared with an earlier study to record the change in water quality over a decade. HCO3 and Na were found exceeding the highest desirable limit of the World Health Organisation (WHO) and Indian Standards Institute (ISI) standards for drinking water. The pH values at seven localities are not within the limits prescribed by WHO or ISI (highest desirable level or maximum permissible level). The present study shows that there has been an enrichment of chemical constituents during the last decade and that the Gurupur River, which flows parallel to the coast, plays an important role in impeding saltwater intrusion along the coast. 相似文献
35.
Measurements of carbon dioxide (CO2) concentration were made at a coastal land station, Goa, on the west coast of India from March to June 2003 as part of the ARMEX (ARabian sea Monsoon Experiment) campaign. The observations show a systematic reduction (~120?mg?m?3) of CO2 concentration during the pre-monsoon months, March–May, during which no significant change in anthropogenic emissions takes place. CO2 shoots up from 520 to 635?mg?m?3 in June with the onset of the South West monsoon. Back trajectories show that the source of air mass gradually shifts from the coastal land mass to the open southern Arabian Sea during the pre-monsoon period. The observed reduction in CO2 is explained in terms of earlier measurements in the Arabian Sea indicating maximum chlorophyll a (Sarupria and Bhargava in J Mar Sci 27:292–297, 1998) and minimum partial pressure of CO2 (Sarma in J Geophys Res 108:3225, 2003) in the sea waters off the west coast of India during the pre-monsoon period, cleaner marine air mass advection from the open sea, and negligible local vertical CO2 flux. 相似文献
36.
Aeromagnetic anomalies over Bastar craton and Pranhita-Godavari (P-G) basin in the south of central India could be attributed
to NW-SE striking mafic intrusives in both the areas at variable depths. Such intrusions can be explained considering the
collision of the Bastar and Dharwar cratons by the end of the Archaean and the development of tensile regimes that followed
in the Paleoproterozoic, facilitating intrusions of mafic dykes into the continental crust. The P-G basin area, being a zone
of crustal weakness along the contact of the Bastar and Dharwar cratons, also experienced extensional tectonics. The inferred
remanent magnetization of these dykes dips upwards and it is such that the dykes are oriented towards the east of the magnetic
north at the time of their formation compared to their present NW-SE strike. Assuming that there was no imprint of magnetization
of a later date, it is concluded that the Indian plate was located in the southern hemisphere, either independently or as
part of a supercontinent, for some span of time during Paleoproterozoic and was involved in complex path of movement and rotation
subsequently. The paper presents a case study of the utility of aeromagnetic anomalies in qualitatively deducing the palaeopositions
of the landmasses from the interpreted remanent magnetism of buried intrusive bodies. 相似文献
37.
Magnetic anomalies of offshore Krishna-Godavari basin,eastern continental margin of India 总被引:1,自引:0,他引:1
K. V. Swamy I. V. Radhakrishna Murthy K. S. Krishna K. S. R. Murthy A. S. Subrahmanyam M. M. Malleswara Rao 《Journal of Earth System Science》2009,118(4):405-412
The marine magnetic data acquired from offshore Krishna-Godavari (K-G) basin, eastern continental margin of India (ECMI),
brought out a prominent NE-SW trending feature, which could be explained by a buried structural high formed by volcanic activity.
The magnetic anomaly feature is also associated with a distinct negative gravity anomaly similar to the one associated with
85°E Ridge. The gravity low could be attributed to a flexure at the Moho boundary, which could in turn be filled with the
volcanic material. Inversion of the magnetic and gravity anomalies was also carried out to establish the similarity of anomalies
of the two geological features (structural high on the margin and the 85°E Ridge) and their interpretations. In both cases,
the magnetic anomalies were caused dominantly by the magnetization contrast between the volcanic material and the surrounding
oceanic crust, whereas the low gravity anomalies are by the flexures of the order of 3–4 km at Moho boundary beneath them.
The analysis suggests that both structural high present in offshore Krishna-Godavari basin and the 85°E Ridge have been emplaced
on relatively older oceanic crust by a common volcanic process, but at discrete times, and that several of the gravity lows
in the Bay of Bengal can be attributed to flexures on the Moho, each created due to the load of volcanic material. 相似文献
38.
Sanjay Gosain Sanjiv Tiwari Jayant Joshi P. Venkatakrishnan 《Journal of Astrophysics and Astronomy》2008,29(1-2):107-111
The Solar Vector Magnetograph (SVM) at Udaipur Solar Observatory saw its first light in April 2005. The retrieval of vector fields from the imaging spectro-polarimetric observational data requires a substantial amount of computer post-processing. The GUI-based data reduction and analysis software have been developed to make the data processing pipeline user-friendly and less time-consuming. In this paper we describe these software packages. 相似文献
39.
The aim of this short note is to test whether the morphological skeletal network (MSN) of water bodies that resembles a river network follows Horton's laws. A fractal relationship of MSN of a water body is also shown. This investigation shows that the MSN of the Nizamsagar reservoir follows Horton's laws. Furthermore, this reservoir has a fractal dimension (D
m) of 1.92 which was computed by using two morphometric quantities and the fractal dimension of the main skeletal length (d). This value tallies exactly with the fractal dimension (D
f) of the whole MSN computed through box-counting method. 相似文献
40.
The aim of this short note is to test whether the morphological skeletal network (MSN) of water bodies that resembles a river network follows Horton's laws. A fractal relationship of MSN of a water body is also shown. This investigation shows that the MSN of the Nizamsagar reservoir follows Horton's laws. Furthermore, this reservoir has a fractal dimension (D m) of 1.92 which was computed by using two morphometric quantities and the fractal dimension of the main skeletal length (d). This value tallies exactly with the fractal dimension (D f) of the whole MSN computed through box-counting method. 相似文献