A square composed of horizontal lines appears taller and narrower than an identical square made up of vertical lines. Reporting this illusion, Hermann von Helmholtz noted that such illusions, in which filled space seems to be larger than unfilled space, were common in everyday life, adding the observation that ladies' frocks with horizontal stripes make the figure look taller. As this assertion...

Abstract Trapped-mode frequencies are computed for submerged, horizontal, circular cylinders in a two-layer fluid consisting of a finite layer bounded above by a free surface and below by a infinite layer of greater density. Two separate cases are considered. First we consider waves which propagate along the top of a single cylinder at frequencies below the cut-off for wave propagation away fro...

We consider upward planar drawings of directed graphs in the plane (UP), and on standing (SUP) and rolling cylinders (RUP). In the plane and on the standing cylinder the edge curves are monotonically increasing in y-direction. On the rolling cylinder they wind unidirectionally around the cylinder. There is a strict hierarchy of classes of upward planar graphs: UP ⊂ SUP ⊂ RUP. In this paper, we ...

Experiments were conducted to obtain the modal damping ratios of two hollow cylinders of different thicknesses of Aluminum. An electro dynamic exciter with slip table is used to excite the hollow cylinders. The hollow cylinder (unit under test) is fastened to the exciter. The exciter is placed in the horizontal direction and connected to the slip table. A control accelerometer is placed at the ...

We studied the evolution of elliptic heavy SF6 gas cylinder surrounded by air when accelerated by a planar Mach 1.25 shock. A multiple dynamics imaging technology has been used to obtain one image of the experimental initial conditions and five images of the time evolution of elliptic cylinder. We compared the width and height of the circular and two kinds of elliptic gas cylinders and analyzed...

We consider free convection in 2D and 3D horizontal cylindrical layers with the inner hot outer cold boundary at Ra (Rayleigh number) range (4?103 ÷ 4?105) ratio ? ? 1:20 of layer width to radius. Prandtl number was 0,71, fluid properties were taken for air 293 K. It shown that flow a can be divided into three regions. Stable symmetric convective rolls are formed layer’s upper part; regions tra...