1,902 research outputs found
Solutional Landforms of Gabal Al-Qaraha, the Oasis of Al-Hasa, Saudi Arabia
Jabal Al-Qarah is one of the small outlier hills at the Oasis of Al-Hasa, lying at about lOkm ENE of Al-Hafuf Town. The solutional forms of Al-Qarah hill discussed in this paper are as follows : 1. A calcareous duricrust which covers the top and some of the slopes of the hill.
2. Rock Pillars which are long columns of white lime-stone.
3. Huge crevasses which are wide erosional openings along vertical joints.
4. Narrow, sinuous caves inside the hill.
5. Pedestal rocks with mushroom-like shape.
Evidences collected from the field suggest that these characteristic solutional forms of Jabal Al-Qarah were developed under a variety of climates by the process of solution, and that their development was controlled by high rock solubility, horizontal beds of varying lithologies, and pronounced vertical joints
Einstein Geometrization Philosophy and Differential Identities in PAP-Geometry
The importance of Einstein's geometrization philosophy, as an alternative to
the least action principle, in constructing general relativity (GR), is
illuminated. The role of differential identities in this philosophy is
clarified. The use of Bianchi identity to write the field equations of GR is
shown. Another similar identity in the absolute parallelism geometry is given.
A more general differential identity in the parameterized absolute parallelism
geometry is derived. Comparison and interrelationships between the above
mentioned identities and their role in constructing field theories are
discussed.Comment: LaTeX file, 17 pages, comments and criticism are welcom
The OIV 1407.3\AA /1401.1\AA\ emission-line ratio in a plasma
Line ratio of O IV 1407.3 \AA/1401.1 \AA\- is calculated using mostly our own
atomic and collisional data. Energy levels and oscillator strengths needed for
this calculation have been calculated using a Hartree-Fock relativistic (HFR)
approach. The electron collision strengths introduced in the statistic
equilibrium equations are fitted by polynomials for different energies.
Comparison has also been made with available theoretical results. The provided
line ratio has been obtained for a set of electron densities from
cm to cm and for a fixed temperature of 50 000 K.Comment: 6 pages, 1 figure, 2 tables. Accepted for publication in Advances in
Space Researc
- …