The Effect of Sources on the Inner Horizon of Black Holes

Single pulse of null dust and colliding null dusts both transform a regular horizon into a space-like singularity in the space of colliding waves. The local isometry between such space-times and black holes extrapolates these results to the realm of black holes. However, inclusion of particular scalar fields instead of null dusts creates null singularities rather than space-like ones on the inner horizons of black holes.Comment: Final version to appear in PR

Prediction of the compressibility behavior of highly plastic clays under high stresses

A simple method is proposed to predict the compressibility behavior of highly plastic clays (bentonites/montmorillonites) under high pressures using data describing their behavior under low pressures. It was shown that the void ratio of the compressible layer at 100 kPa is an effective normalizing factor to predict the void ratio at higher pressures. Experimental results from the published literature on highly plastic clays were used to verify the proposed procedure. The different normalized equations, that are, i) e/e(100) vs. log pressure p and ii) e/e(100) with 1/root p, were studied. Both of the equations yielded very good results in predicting the compressibility behavior under high pressures. Extremely high correlation was found out to exist between the proposed equation and the equation obtained using the diffuse double layer theory. Given the need to obtain the compressibility behavior and the difficulties involved in the experimental work to obtain reliable results at high pressures, the proposed method was found out to be very effective. (c) 2010 Elsevier B.V. All rights reserved

Swelling behaviour of compacted fine-grained soils

The swelling behaviour of three compacted Cyprus soils varying significantly in their physical properties have been studied with variation in compaction energies from standard Proctor compaction to modified Proctor. For comparison, studies have also been made with kaolinite and a highly plastic montmorillonitic clay. Both percent swell and swelling pressure are significantly influenced by the compaction energy. There is an unique relationship between percent swell and the swelling pressure irrespective of the soil type and the level of compaction energy. The percent swell–time relationship could be identified as a rectangular hyperbola facilitating the prediction of ultimate percent swell with a few initial results. The swell–log time relationship has three distinct phases of initial, primary, and secondary swelling. The secondary swell could be distinctly identified, and a knowledge of the rate of secondary swelling enables the prediction of long-term swelling. The study focuses on the attention of the significant influence of the compaction energy on percent swell/swelling pressure

Compaction behaviour and prediction of its characteristics of fine grained soils with particular reference to compaction energy

Field compaction of fine grained soils usually involves different equipments with the compaction energy varying significantly. Hence the compaction characteristics (maximum dry unit weight and optimum moisture content) need to be obtained at different compaction energies. Thus knowledge of compaction behaviour and its characteristics of fine grained soils at different compaction energies assumes great importance from the viewpoint of practical significance. In this paper the effect of compaction energy on the behaviour and compaction characteristics of fine grained soils has been brought out. It has been seen that the optimum moisture content bears a good relation with plastic limit and the maximum dry unit weight correlating well with the dry unit weight of soil at plastic limit for all compaction energies studied. Apart from the experimental data obtained by the authors, extensive results from literature have also been used in the analysis. In view of large quantities of soils from different borrow pits to be tested for their potential use, the above correlation with plastic limit enables not only saving of time but also cost of investigation for preliminary design

Swelling behaviour of compacted fine-grained soils

The swelling behaviour of three compacted Cyprus soils varying significantly in their physical properties have been studied with variation in compaction energies from standard Proctor compaction to modified Proctor. For comparison, studies have also been made with kaolinite and a highly plastic montmorillonitic clay. Both percent swell and swelling pressure are significantly influenced by the compaction energy. There is an unique relationship between percent swell and the swelling pressure irrespective of the soil type and the level of compaction energy. The percent swell-time relationship could be identified as a rectangular hyperbola facilitating the prediction of ultimate percent swell with a few initial results. The swell-log time relationship has three distinct phases of initial, primary, and secondary swelling. The secondary swell could be distinctly identified, and a knowledge of the rate of secondary swelling enables the prediction of long-term swelling. The study focuses on the attention of the significant influence of the compaction energy on percent swell/swelling pressure