The packing chromatic number χρ(G) of a graph G is the smallest integer k needed to proper color the vertices of G in such a way that the distance in G between any two vertices having color i be at least i+1. Goddard et al. [8] found an upper bound for the packing chromatic number of hypercubes Qn. Moreover, they compute χρ(Qn) for n ≤ 5 leaving as an open problem the remaining cases. In this p...

Dipolar colloidal particles self-assemble into a rich variety of microstructures ranging from co-crystals of unusual symmetry, to open networks (gels) of cross-linked chains of particles. We use molecular dynamics computer simulation to explore the self-assembly, structure, crystallization and/or gelation of systems of colloid particles with permanent dipole moments immersed in a high-dielectri...

Ich habe diesen Sommer mein Abi gemacht und möchte zum Herbst mit dem Studium beginnen – Informatik natürlich! Da es in meinem kleinen Ort keine Uni gibt, werde ich deshalb in Kürze umziehen müssen. Dann heißt es, all die tausend Sachen in meinen Schränken und Regalen in Umzugskartons zu verpacken. Um den Umzug möglichst kostengünstig zu gestalten, werde ich mich dabei bemühen, die Gegenstände ...

The two-dimensional strip packing is a special case of “Cutting and Packing” problems that arises in many applications. The problem seeks to pack a given set of rectangles into a strip of given width in order to minimize its length. Some applications in which the strip packing problem arises are: Cutting pieces from wooden boards, cutting pieces from glass or steel sheets, optimal layout of ind...

We present a new lemma stating that, given an arbitrary packing of a set of rectangles into a larger rectangle, a “structured” packing of nearly the same set of rectangles exists. This lemma has several implications on the approximability of 2-dimensional packing problems. In this paper, we use it to show the existence of a polynomial-time approximation scheme for 2-dimensional geometric knapsa...

OBJECTIVES Temporary abdominal closure methods allow for management of open abdomens where immediate primary closure is not possible and/or where repeat abdominal entries are necessary. We assessed pressure mapping and fluid extraction efficiency of three open abdomen dressing systems: ABThera(™) Active Abdominal Therapy System, V.A.C.(®) Abdominal Dressing System, and Barker's vacuum packing t...

This paper considers the optimized packing of different spheres into a given spherical container under non-standard placement conditions. A sphere is considered placed in if at least certain part container. Spheres are allowed to overlap with each other according predefined parameters. Ratio conditions introduced establish correspondence between number packed radii. The aims maximize total subj...

Brass Ferrules have been used as packing in a laboratory- scale glass distillation column approaching pilot plant size because of their availability in all sizes and low cost. The available size range is such that these ferrules could also be used in industry and the results of this study could be scaled up. The performance of the new packing has been compared with the performance of glass ...

In a previous paper, pressure drop, flooding and mass-transfer characteristics of a novel pilot-scale distillation column called spinning cone column (SCC) were presented. Here, we present the result of comparison of mass-transfer efficiencies of SCC and structured packing. Comparison of SCC and structured packing mass-transfer characteristics show that the gas and liquid-side height of transfe...