in this study, boundary element method was used to model sea wave propagation on a hemisphere shape under water tank and oil-water common surface oscillation in the tank. also, kinematic and dynamic oundary conditions of free surface and common surface of oil and water were discritized by finite difference method. there were some singularities in bem method, which were removed by applying zonin...

Pipes are widely used in many industrial and mechanical applications and devices. Although there are many different constructions according to the specific application and device, these can show helical pattern, such as spiral pipes, wire-reinforced pipes/shells, spring-suspension, and so on. Theoretical modelling of wave propagation provides a prediction about the dynamic behavior, and it is f...

However it is possible to use of numerical methods such as beta-Newmark in order to investigate the structural response behavior of the dynamic systems under random sea wave loads but because of necessity to analysis the offshore systems for extensive time to fatigue study it is important to use of simple stable methods for numerical integration. The modified Euler method (MEM) is a simple nume...

Wave propagation in unbounded layered media with a new formulation of Axisymmetric Scaled Boundary Finite Element Method (AXI-SBFEM) is derived. Dividing the general three-dimensional unbounded domain into a number of independent two-dimensional ones, the problem could be solved by a significant reduction in required storage and computational time. The equations of the corresponding Axisymmetri...

Observations of the radio remnant of Supernova 1987A using the Australia Telescope Compact Array in the 12-mm band on 2003 July 31 (day 6002.7 after the explosion) give the first fully resolved radio image of the supernova remnant. The diffraction-limited image has a resolution of about 0.45, a factor of two better than that of the 3-cm images previously obtained. There is excellent agreement b...

Aims. We present results from sensitive, high dynamic range, observations to search for extended diffuse radio emission in relaxed and cool-core galaxy clusters. Methods. For this purpose we performed deep 1.4 GHz Very Large Array observations, of A1068, A1413, A1650, A1835, A2029, and complemented our dataset with archival observations of Ophiuchus. Results. We find that in the central regions...

The important characteristic of sea waves is their high energy density, which is the highest among renewable energy sources. Having up to 2700 km. of shoreline, Iran has a great potential in construction of offshore wave buoys (hereafter called OWB). In this article a OWB model with the possibility of assembling different buoy configurations is introduced. The system is exposed to regular and i...