Given a line arrangement A with n lines, we show that there exists a path of length n/3−O(n) in the dual graph of A formed by its faces. This bound is tight up to lower order terms. For the bicolored version, we describe an example of a line arrangement with 3k blue and 2k red lines with no alternating path longer than 14k. Further, we show that any line arrangement with n lines has a coloring ...

The realizability problem for rank 3 oriented matroids (see [1]) is equivalent to the pseudoline stretchability problem (see [4]). This paper uses an example to illustrate a new approach to this problem. The main theorem of this paper, like the trigonometric form of Ceva’s theorem, shows a non-trivial relationship amongst the angles in a specific line arrangement figure (c). We work in polar co...

This paper presents the experimental study of pressure and velocity fluctuations and their interdependence, in the turbulent flow impinging on arrangements of yawed circular cylinders simulating inclined tube banks with square arrangement and a pitch to diameter ratio of 1.26. Measurements were performed with hot-wires and a pressure transducer. Behaviour of fluctuating quantities is described ...

This paper presents a three-dimensional numerical and experimental geometric optimization study to maximize the total heat transfer rate between a bundle of finned tubes in a given volume and external flow, for staggered arrangements of circular and elliptic tubes. Experimental results were obtained for circular and elliptic configurations with twelve tubes, starting with an equilateral triangl...

the effect and arrangement of cytoskeleton (microtubules, microfilaments and neurofilaments) in neurulation of chick embryo examined by immunoperoxidase method from stage 6 to stage 12. the results were as follows: 1) microtubules aggregated in the perinuclear region from which they radiated to take longitudinal course beneath the membrane. 2) microfilaments were aggregated in the apical ends (...

Eddy current testing (ECT) is a conventional inspection method of heat exchanger tubes. Many types of probes have been developed depending on such tube conditions as tube shapes and materials. However, the vicinity of a tube expansion is still a difficult area to inspect. This is because there is a step-shape variation circumferentially on the inside surface and there is a ferromagnetic tube sh...