In this communication, we report a physical method for the fabrication of organic solvent and surfactant-resistant barriers on paper-based fluidic devices. When nonwoven polypropylene sheet is embossed with a steel mold, the embossed region acts as a physical barrier that can prevent the flow of liquids. Embossed polypropylene barriers not only block water, but also block organic solvents and s...

This paper describes 4-valent tiling-like structures, called pseudotilings, composed of barrel tiles and apeirogonal pseudotiles in Euclidean 3-space. These (frequently face-to-face) pseudotilings naturally rise in columns above 3-valent plane tilings by convex polygons, such that each column is occupied by stacked congruent barrel tiles or congruent apeirogonal pseudotiles. No physical space i...

The researchers randomly assigned 90 children to conditions in which they learned using different kinds of physical interaction with the material. In one group, children picked up magnetic number tiles and put them in the proper place in the formula. For example, for the problem 4 + 2 + 6 = ___ + 6, they picked up the 4 and 2 and placed them on a magnetic whiteboard. Another group mimed that ac...

We use the abstract tile assembly model of Winfree [6], which models the aggregation of monomers called tiles that attach one at a time to a growing structure, starting from a single seed tile, in which bonds (“glues”) on the tile are specific (glues only stick to glues of the same type on other tiles) and cooperative (so that multiple weak glues are necessary to attach a tile). The general ide...

This paper opens a new chapter in the study of planar tilings by introducing conformal tilings. These are similar to traditional tilings in that they realize abstract patterns of combinatorial polygons as concrete patterns of geometric shapes, the tiles. In the conformal case, however, these geometric tiles carry prescribed conformal rather than prescribed euclidean structure. The authors devel...

Abdus-Salam School of Mathematical Sciences, GCU, 35-C-2 Gulberg -III Lahore, Pakistan [email protected] [email protected] key words: rectangle, tiling, trapped block. Abstract. In this paper, we prove that if a finite number of rectangles, every of which has at least one integer side, perfectly tile a big rectangle then there exists a strategy which reduces the number of these tiles...

Abstract. Remote Sensing is an important source of information about the dynamics of Earth's land and oceans, but retrieve information from this technique, is a challenge. Segmentation is a traditional method in remote sensing, which have a high computational cost. An alternative to suppress this problem is use parallel approaches, which split the image into tiles, and segment each one individu...

Abstract. This investigation studies the decidability problem of plane edge coloring with three symbols. In the edge coloring (or Wang tiles) of a plane, unit squares with colored edges that have one of p colors are arranged side by side such that the touching edges of the adjacent tiles have the same colors. Given a basic set B of Wang tiles, the decision problem is to find an algorithm to det...

We consider the history of certain modular elements: Op-tiles, Kufic tiles, and key-patterns, which occur as ornamental archetypes from Paleolithic times until the present. Paleolithic ornaments We have found that the oldest examples of ornamentation in Paleothic art were from Mezin (Ukraine) dated to 23 000 B.C. Note that 23 000 years is a time period ten times longer than the complete written...

If asked to produce a list of current economists whose work will most influence the development of economics over the next 50 years, I would put Vernon Smith’s name close to the top. As Smith (1987) once remarked, economics has been traditionally considered an ‘‘observational’’ science like astronomy or meteorology, rather than an experimental science like physics or chemistry. The great accomp...