Birkhoff-type theorem for electromagnetic fields in self-creation cosmology

A result having formal similarity to Birkhoff's theorem in general relativity has been proved in the presence of electromagnetic fields in a self-creation theory of gravitation proposed by Barber, when the scalar field is independent of time.     

Robertson-walker type Lyttleton-Bondi universe

The exterior field of the Robertson-Walker type metric in the Lyttleton-Bondi universe is considered and an exact solution is obtained. Some physical properties of the solution are discussed.     

Subcrustal Low Velocity Layers in Central India and their Implications

A 2-D subcrustal velocity model for the central Indian continental lithosphere has been derived by travel time and relative amplitude modeling of a digitally normalized analog seismic record section of the Hirapur-Mandla DSS profile, using a ray-tracing technique. Some prominent wave groups with apparent velocities slightly higher than the Moho reflection phase (P_MP) are identified on the normalized record sections assembled with a reduction velocity of 6 km s⁻¹. We interpret these phases as the wide-angle reflections from subcrustal lithospheric boundaries. Comparison of synthetic seismograms with the observed record section shows that the observed phases cannot be explained either by multiples or by the P-to-S converted phase (P_MS) from the Moho. Subcrustal velocity models either with a velocity increase or with a single low velocity layer (LVL) also do not provide a satisfactory fit. We infer that a subcrustal velocity model with two alternate LVLs (velocity 7.2 km s⁻¹), separated by a 6-km thick high velocity layer (velocity 8.1 km s⁻¹), can satisfy both the observed travel times and amplitudes. The prominent reflection phases are modeled at depths of 49, 51, 57 and 60 km. It is inferred that the subcrustal lithosphere in the central Indian region has a lamellar structure with varying structural and mechanical properties. The alternating LVLs, occurring at relatively shallow depths below Moho, may be associated with the zones of weakness and lower viscosity suggesting continued mobility, with a possible thermal source in the upper mantle. This explains the source of observed high heat flow values in the central Indian region.     

Adsorption of heavy metals in glacial till soil

The charged sites on soil particles are important for the retention/adsorption of metals. Metallic counterions can neutralize the intrinsic charges on the surfaces of soil particles by forming complexes. In this study, efforts have been made to determine the effect of surface potential, pH, and ionic strength on the adsorption of four metal ions, hexavalent chromium Cr(VI), trivalent chromium Cr(III), nickel Ni(II) and cadmium Cd(II), in glacial till soil. Batch tests were performed to determine the effect of pH (2–12) and ionic strength (0.001–0.1 M KCl) on zeta potential of the glacial till soil. The point of zero charge (pH _PZC ) of glacial till was found to be 7.0±2.5. Surface charge experiments revealed the high buffering capacity of the glacial till. Batch adsorption experiments were conducted at natural pH (8.2) using various concentrations of selected metals. The adsorption data was described by the Freundlich adsorption model. Overall glacial till shows lower adsorption affinity to Cr(VI) as compared to cationic metals, Cr(III), Ni(II) and Cd(II).     

List of Forthcoming Papers

Other Index

List of Forthcoming Papers     

Variation of lunar and solar geomagnetic tides with sunspot and geomagnetic activity

Summary Solar and lunar geomagnetic tides inH at Alibag have been determined by spectral analysis of discrete Fourier transforms following the method of Black and the well-known Chapman-Miller method. The seasonal variation inL ₂(H) is opposite to that inL ₂(D) with maximum in thed season and minimum in thej season. In bothH andD the enhancement due to sunspot activity is larger in lunar tide than in solar tide. Surprisingly, the enhancement due to magnetic activity is greater inL ₂(H) than inS ₁(H), while the contrary is true for declination. It is inferred that there is a local time component of the storm time variation contrary to the view expressed by Green and Malin. The enhancements in amplitudesL ₂ andS ₁ inH andD, due to sunspot activity and due to magnetic activity, have been separated. The results show that the amplitude at zero sunspot number increases with magnetic activity in all the four parameters, while the enhancement due to sunspot activity at different levels of magnetic activity decreases with increase ofK _p. But if bothK _p andR are increasing, whenK _p increases enhancement due toR decreases and whenR increases enhancement due toK _p decreases.     

The influence of barrier beach on sediment transportation in the Kakinada Bay

Summary Studies upon the changes of bottom topography in the vicinity of Godavari point and Kakinada Bay indicates recession of contours towards the shore as a result of net loss of sediment since the formation of Kakinada Bay. The sand spit has been growing in the north-westerly direction reducing the width of the opening between the Kakinada Bay and the open Ocean. The currents across the opening strengthen resulting rapid erosion of the bottom of the Bay. The beach to the north of the Kakinada Bay entrance channel is building up. In the present investigation, the authors made an attempt to explain the shore line changes and changes in bottom topography in the Kakinada Bay from the currents measured under different tidal conditions around the sand spit (Godavari Point.)     

Mineralogy and chemistry of the iron ores of Nainarmalai,Tamilnadu

The magnetite-quartzites of Nainarmalai forms part of a large iron ore belt of Tamilnadu which occurs in a high grade granulite terrain. They are associated with basic granulites and gneisses. Mineralogical and chemical studies indicate their similarities with other metasedimentary iron ores.     

Analysis and planning of Saharanpur region for development and growth using remote sensig techniques

In this study the analysis of Saharanpur region has been done at Roorkee University for the development and growth of the region, using Landsat Imagery of November, 1972 (Bands 5 and 7) after enlarging it to a Scale of 1:250,000. Land utilization map (by visual interpretaion) was prepared, on the base map obtained from 250,000 toposheet, interpreting three main element of the image i.e. tone, texture and pattern-Sample verification of the landuses obtained was done by the interpretation of 1:10,000 scale photos for plains and 1:60,000 scale photographs for hilly area and found quite reasonable. Some of the information about population and the distribution of population according to the sizes of the settlements are found by the census report. The road work information is obtained from the toposheet and aerial photographs. After getting this information, hierarchy of settlements, land utilizaton onward settlement, population of the settlements, road conncetions between settlements and the size of the settlements are determined. The strategy for development of Growth centres is thought out and the facilities of these Growth centres are proposed. It has been found that the remote sensing technique gives a hierarchy by which optimum location of growth centres in the region is comparatively very easy, time saving and economical.