The development of a process to emplace a refractory metal liner inside a gun tube is described. The process consists of filling the liner with an elastomeric material and then slipping this arrangement into the gun tube. The ends of the liner are plugged with plastic disks and pressure is applied to the elastomeric material by a load frame. The original clearance between the liner and gun tube...

We introduce a new combinatorial object, the double-permutation sequence, and use it to encode a family of mutually disjoint compact convex sets in the plane in a way that captures many of its combinatorial properties. We use this encoding to give a new proof of the Edelsbrunner-Sharir theorem that a collection of n compact convex sets in the plane cannot be met by straight lines in more than 2...

Microchannel heat exchangers (MCHX) are being increasingly applied in heat pumps because of their compactness, significant charge reduction, lower refrigerant pressure drop and lower air-side fan power consumption compared to traditional round tube-plate fin (RTPF) heat exchangers. Using a microchannel condenser as well as evaporator in a heat pump system also offers significant potential for c...

To a set of n points in the plane, one can associate a graph that has less than n2 vertices and has the property that k-cliques in the graph correspond vertex sets of convex k-gons in the point set. We prove an upper bound of 2k−1 on the size of a planar point set for which the graph has chromatic number k, matching the bound conjectured by Szekeres for the clique number. Constructions of Erdős...

Abstract In this work, an experimental study on new series connection of two Ranque-Hilsch vortex tubes with generator materials, potential in seawater desalination was implemented, combined modification has not been studied open literature. Polycarbonate and Polyamide-Nylon 6 were tested compared as materials that enhance the heat transfer between air streams inside tube. Moreover, using prehe...

The Strong Dirac conjecture, open in some form since 1951 [5], is that every set of n points in R includes a member incident to at least n/2 − c lines spanned by the set, for some universal constant c. The less frequently stated dual of this conjecture is that every arrangement of n lines includes a line incident to at least n/2 − c vertices of the arrangement. It is known that an arrangement o...

A simplicial arrangement of pseudolines is a collection of topological lines in the projective plane where each region that is formed is triangular. This paper refines and develops David Eppstein’s notion of a kaleidoscope construction for symmetric pseudoline arrangements to construct and analyze several infinite families of simplicial pseudoline arrangements with high degrees of geometric sym...

We describe a linear-time algorithm that finds a planar drawing of every graph of a simple line or pseudoline arrangement within a grid of area O(n). No known input causes our algorithm to use area Ω(n ) for any > 0; finding such an input would represent significant progress on the famous k-set problem from discrete geometry. Drawing line arrangement graphs is the main task in the Planarity puz...

The effects of tracheal tube of cuff on dog tracheal mucosa were studied by scanning electron microscopy. Additionally, specimens of human tracheal epithelium were investigated. The specimens obtained from total laryngetomy cases under endotracheal intubation anesthesia for 3 to 6 hours. In injured areas of dog and human tracheal mucosa normal ciliary arrangement was disturbed and the cilia bec...

A vast selection of different ozone generator designs is commercially available on today’s market. In large-scale applications, the ground electrode is designed as gas/water tube heat exchanger, which is filled with tubular high-voltage electrodes on the gas processing side. Available constructions differ in diameter, length and arrangement of the tubular electrodes, type and support of the die...