the majority of iran’s area is covered by arid and semiarid climates. in these areas, wind causes more erosion compared to water. therefore, determination of wind characteristics especially its velocity is very important. one of the simplest methods that can supply researchers with the origin of wind erosion in the shortest time is synthesizing sand rose model and interpretation of aerial photo...

While the existing structures, even recently constructed ones are subjected to the critical earthquakes, the catastrophic devastations are expected to occur. Therefore, at least for several important structures such as power plants, infrastructure, and buildings, there is a need to consider the critical excitation analysis. One of the important criteria in the seismic design of the structures u...

In this article, turbulent flow heat transfer in the air gap between rotor and stator of a generator under nonhomogeneous heat flux is studied experimentally. The rotor consists of four symmetrical triangular grooves. The stator surface is smooth and does not include any grooves. The relative heat flux between the rotor and the stator is 1 to 3. Temperature and heat flux are measured locally at...

Magnetic abrasive finishing (MAF) is a micromachining process that uses magnetic field and magnetic abrasive particles to conduct the mechanism of material removal in micro-nanometer scales. In this paper, by an experimental method and statistical analysis, the effects of parameters like working gap, work-piece rotational speed and material removal mechanism (injection of abrasive slurry of Al<...

In this paper, optimal design of hybrid low damping base isolation and magnetorheological (MR) damper has been studied. Optimal hybrid base isolation system has been designed to minimize the maximum base drift of low damping base isolation system where for solving the optimization problem, genetic algorithm (GA) has been used. In design procedure the maximum acceleration of the structure has ...

The combined use of 3D scanning lasers with 2D cameras has become increasingly popular in mobile robotics, as the sparse depth measurements of the former augment the dense color information of the latter. Sensor fusion requires precise 6DOF transforms between the sensors, but hand-measuring these values is tedious and inaccurate. In addition, autonomous robots can be rendered inoperable if thei...

There is evidence that spiral waves and their breakup underlie mechanisms related to a wide spectrum of phenomena ranging from spatially extended chemical reactions to fatal cardiac arrhythmias [A. T. Winfree, The Geometry of Biological Time (Springer-Verlag, New York, 2001); J. Schutze, O. Steinbock, and S. C. Muller, Nature 356, 45 (1992); S. Sawai, P. A. Thomason, and E. C. Cox, Nature 433, ...

We investigate a model for the dynamics of ellipsoidal microswimmers in an externally imposed, laminar Kolmogorov flow. Through phase-space analysis without noise, we find that swimmers favor either cross-stream or rotational drift, depending on their swimming speed and aspect ratio. When including i.e., diffusion, are driven into certain parts phase space, leading to nonuniform steady-state di...