Bottom intake is an intake structure which can be considered as an alternative for regular intakes in mountain streams Water in in taking from river are very vast and complicated issues, each project has special characteristics which should be considered. Water intake from riveris generally based on Pump and gravity method. The gravity method is more useful and common because of continuity and ...

The instability against emission of massless particles by the trapping horizon of an evolving black hole is analyzed with the use of the Hamilton-Jacobi method. The method automatically selects one special expression for the surface gravity of a changing horizon. Indeed, the strength of the horizon singularity turns out to be governed by the surface gravity as was defined a decade ago by Haywar...

generally, gravity anomaly is the difference between the observed acceleration of earth's gravity and a normal value. topography (all masses above geoid) plays a main role in definition of the gravity anomaly. based on modeling of the effect of topography, there are different models of gravity anomaly such as free-air and bouguer anomaly. the main goal of the bouguer anomaly is removing of...

The energy conservation method is based on knowledge of the state vector and measurements of nonconservative forces. This is or will be provided by CHAMP, GRACE and GOCE. Here the analysis of one month of CHAMP state vector and accelerometer data is described. The energy conservation method is used to estimate the gravity potential at satellite altitude. When doing so we consider the tidal pote...

Aseismic safety of dam involves people’s lives and properties, even has a great impact on national economic development. The key to this project is to have a fairly complete fluid-structure interaction (FSI) theory and a calculation method with a good accuracy. Therefore, focused on the FSI dynamic problem of gravity dam under seismic action, this paper presented the non-linear 2.5D dynamic the...

We measured the amount of visual movement judged consistent with translational head movement under normal and microgravity conditions. Subjects wore a virtual reality helmet in which the ratio of the movement of the world to the movement of the head (visual gain) was variable. Using the method of adjustment under normal gravity 10 subjects adjusted the visual gain until the visual world appeare...

This study numerically predicts the failure scenario of a cracked concrete gravity dam through a push-over nonlinear analysis. The mixed-mode Linear Elastic Fracture Mechanics (LEFM) was employed using the extended finite element method (XFEM). The dam base was considered to be fully fixed without any foundation effects. The hydrostatic pressure on the dam's upstream face was increased incremen...

Coal mining subsidence seriously affects the mine natural and ecological environment. Leveling is the traditional method to monitor the coal mining subsidence. It is possible to monitor the subsidence by gravimetry instead of leveling based on the negative linear correlation between the gravity change and the height change. Equations are derived to monitor the subsidence by gravimetry in the pa...

In order to obtain sufficiently accurate spherical harmonic model of asteroid’s gravity field during the design stage of asteroid exploration mission which we can benefit from to design the orbit trajectory or the landing trajectory, the author of this paper proposed a method to determine the spherical harmonic model of asteroid’s gravity field based on polyhedron model. Firstly, this method re...

in this paper, eringen’s nonlocal elasticity and timoshenko beam theories are implemented to analyze the bending vibration for non-uniform nano-beams.  the governing equations and the boundary conditions are derived using hamilton’s principle. a generalized differential quadrature method (gdqm) is utilized for solving the governing equations of non-uniform timoshenko nano-beam for pinned-pinned...