This paper is a study of the hamiltonicity of proper interval graphs with applications to the guard problem in spiral polygons. We prove that proper interval graphs with ~> 2 vertices have hamiltonian paths, those with ~>3 vertices have hamiltonian cycles, and those with />4 vertices are hamiltonian-connected if and only if they are, respectively, 1-, 2-, or 3-connected. We also study the guard...

bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. high mixing that result in high heat and mass transfer rates are amongst their advantages. heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

Plant-based bioinspired magnetically propelled helical microswimmers are described. The helical microstructures are derived from spiral water-conducting vessels of different plants, harnessing the intrinsic biological structures of nature. Geometric variables of the spiral vessels, such as the helix diameter and pitch, can be controlled by mechanical stretching for the precise fabrication and c...

This paper proposes a novel spiral-double ground heat exchanger (GHX) that decreases conventional construction costs, facilitates installation, promotes transfer, and reduces thermal resistance. In this study, new effective installation procedure was proposed. Three-dimensional, transient, conjugated finite volume simulations were conducted to compare the thermo-hydraulic performance of traditi...

Since the development of multi-slice helical CT, cone-beam reconstruction with a helical vertex path is receiving increasing attention. The current multi-slice CT scanners are adopting a class of approximate reconstruction algorithms which can be viewed an extension of the 2-D FBP algorithm. However, these approximate algorithms break down as the pitch of helix becomes large. In fact, major com...

Raptors - falcons, hawks and eagles in this study - have two regions of the retina in each eye that are specialized for acute vision: the deep fovea and the shallow fovea. The line of sight of the deep fovea points forwards and approximately 45 degrees to the right or left of the head axis, while that of the shallow fovea also points forwards but approximately 15 degrees to the right or left of...

This paper presents a fuzzy analysis technique for pitch class determination that improves the accuracy of key finding from audio information. Errors in audio key finding, typically incorrect assignments of closely related keys, commonly result from imprecise pitch class determination and biases introduced by the quality of the sound. Our technique is motivated by hypotheses on the sources of a...

Realizing conversion between fluid power and mechanical energy, the closed circuit axial piston transmission (CCAPT) plays a vital indispensable role in miscellaneous industries. The frictional loss leakage inside system give rise to inevitable temperature rise. In order prolong life of device, cooling structure on outside CCAPT is designed for promoting heat dissipation. Based relevant transfe...

The main purpose of this paper is to study the hamiltonicity of proper interval graphs and applications of these graphs to the guard problem in spiral polygons. The Hamiltonian path (circuit) problem is, given an undirected graph G = (V ,E), to determine whether G contains a Hamiltonian path (circuit). These two problems are well-known N P-complete problems. In the rst part of this paper, we sh...