Noble metals and gases are very sensitive to the late accretion to the Earth of asteroids and comets. We present mass balance arguments based on these elements that indicate that 0.7 − 2.7 × 10 kg of extraterrestrial bodies struck the Earth after core formation and that comets comprised less than 10 by mass of the impacting population. These results imply that the dynamics of asteroids and come...

methods in this study, 16 skilled female gymnasts (mean age of 9.62 ± 1.45 years) were randomly categorized to two general warm-up with no stretching (ns, n=8) and general warm-up plus static stretching (ss, n=8) groups. the warm-up protocol included a 10-minute jogging, and the static stretch (ss) protocol included stretching programs on the different parts of body during four weeks, three tim...

Utilization is one of the main managerial factors that is applied for construction process analysis well. It directly affects the project duration and construction costs. Therefore, a utilization study in tunneling projects is essential. In this work, the utilization of an earth pressure balance Tunnel Boring Machine (TBM) in Tabriz urban railway project was studied using the Monte Carlo simula...

Abstract Ionospheric structure is characterized by the space–time variation of electron density. However, our understanding physical processes that initiate and sustain intermediate-scale development does not relate directly to statistical measures characterize structure. Consequently, high-resolution physics-based equatorial plasma bubble simulations are essential for identifying systematic re...

Part 1: The Earth and its Lithosphere Chemical composition and structure of the Earth. . . . . . . . . . . . . . . . . . . . . . . . . 3 The structure of the Earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Primordial chemistry: Origin of the elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Formation and evolution of the earth. . . ...