The critical tube diameter problem for quasi-detonations is studied via experiments and two-dimensional numerical simulations based on the reactive Euler equations. In experiments, quasi-detonation in stoichiometric acetylene-oxygen mixtures generated rough-walled tubes with three different diameters, where wall roughness introduced by using spiral inserts wire diameters. Photodiodes are placed...

In the present study, the local characteristics of pressure drop and heat transfer are investigated experimentally for the condensation of a pure refrigerant R134a in multi-port extruded tubes of 8 channels in 1.36mm hydraulic diameter and 19 channels in 0.80mm hydraulic diameter. The experimental data of frictional pressure drop (F.P.D.) and condensation heat transfer coefficient (H.T.C.) are ...

An acoustically transparent, configurable microphone array with omnidirectional elements, designed for room acoustics analysis and synthesis, and archaeological acoustics applications, is presented. Omnidirectional microphone elements with 2 mm-diameter capsules and 1 mm-diameter wire mounts produce a nearly acoustically transparent array, and provide a simplified mathematical framework for pro...

In this paper, we consider an open tube of diameter ε > 0, on the side of which a small hole of size ε2 is pierced. The resonances of this tube correspond to the eigenvalues of the Laplacian operator with homogeneous Neumann condition on the inner surface of the tube and Dirichlet one the open parts of the tube. We show that this spectrum converges when ε goes to 0 to the spectrum of an explici...

Abstract: The diameter and configuration of tubes are important design parameters of power condensers. If a proper tube diameter is applied during the design of a power unit, a high energy efficiency of the condenser itself can be achieved and the performance of the whole power generation unit can be improved. If a tube assembly is to be replaced, one should verify whether the chosen condenser ...

this paper presents a three-dimensional numerical investigation carried out in turbulent forced convection in a tube with helical ribs. enhancement of heat transfer using helically corrugated tubes has beenstudied experimentally by many researchers but there exist a few published numerical analyses results. the paper also introduces the results of heat transfer and friction factor data for inco...

AIMS This study describes a prospective consecutive case series of the initial six eyes of five patients undergoing implantation of the trabecular bypass tube shunt. METHODS A prospective consecutive case series. The initial six eyes of five patients with uncontrolled open angle glaucoma who had never previously undergone ocular surgery. Implantation of the trabecular bypass tube shunt measur...

We show that the existence of a maximal embedded tube in a hyperbolic n-manifold implies the existence of a certain conical region. One application is to establish a lower bound on the volume of the region outside the tube, thereby improving estimates on volume and estimates on lengths of geodesics in small volume hyperbolic 3-manifolds. We also provide new bounds on the injectivity radius and ...

PURPOSE To compare the clinical effects of the single wide-diameter bicanalicular silicone tube and the double bicanalicular silicone tube in endonasal dacryocystorhinostomy (DCR) with canalicular trephinization for canalicular obstruction. METHODS We retrospectively reviewed the records of 121 patients with monocanalicular or common canalicular obstruction who had undergone endonasal DCR wit...

objective: the aim of the present study was to retrospectively evaluate small-diameter (3.3 mm) straumann® dental implants placed in the maxilla or the mandible over a period of 5 years in function. materials and methods: twenty- eight partially edentulous patients received a total of 48 implants over a 5-year period. after the standard healing period (3 to 6 months), the implants were restored...