Our selection of new super greenhouse gases to fill a putative "window" in a future Martian atmosphere relies on quantum-mechanical calculations. Our study indicates that if Mars could somehow acquire an Earth-like atmospheric composition and surface pressure, then an Earth-like temperature could be sustained by a mixture of five to seven fluorine compounds. Martian mining requirements for repl...

Determining the construction areas of retaining wall in order to reduce flooding lands Mehrgerd village due flood flow caused by failure earth dam Ghare Aghach

Estimation of sediment transport load due to erosion in river basins is one of the issues which is indispensable for many projects related to water resources, soil and damps construction. With regards to the phenomenon of erosion and transmission Sedimentation in rivers has always led to deformation in the seaboard and sedimentation, so the management and planning in bank of rivers is important...

Tooth 16 showed a fractured mesial marginal ridge that was undermined by caries (Figure 1). Following the placement of a rubber dam, the tooth was prepared and a medium-sized Class-II cavity resulted (Figure 2). In order to achieve optimum adhesion to enamel, it is essential to prepare the enamel margins in such a way that the enamel prisms are obliquely cut. This entails bevelling of the verti...

PLATO OBSERVED IT, THE OLD TESTAMENT TAUGHT IT, and Thomas Robert Malthus feared it. It has been called the principle of plenitude, which "presupposes a richness, an expansiveness of life, a tendency to fill up, so to speak, the empty niches of nature; implicit is the recognition of the great variety of life and perhaps its tendency to multiply."1 For all living things, the bibli cal injunction...