This paper investigates the parametric study of the empty and foam-filled end-capped tubes under quasi static and dynamic loadings. The numerical crash analysis of the empty and foam-filled tubes was performed using the explicit finite element code ABAQUS- explicit. Satisfactory agreements were generally achieved between the numerical and experimental results. In order to determine the crash be...

OBJECTIVE The purpose of this study is to evaluate the airway dynamics of the upper airway as depicted on cine MRI in children with tracheotomy tubes during two states of airflow through the upper airway. MATERIALS AND METHODS Sagittal fast gradient echo cine MR images of the supra-glottic airway were obtained with a 1.5T MRI scanner on seven children with tracheotomy tubes. Two sets of image...

In this paper, crashworthiness characteristics of conical steel tubes stiffened by annular rings and rigid polyurethane foam are investigated. For this purpose, wide circumferential rings are created from the outer surface of the conical tube at some determined areas along tube length. In fact, this method divides a long conical tube into several tubes of shorter length. When this structure is ...

Application of nanofluid and coiled tubes are two passive methods for increasing the heat transfer. In the present study, the turbulent flows of water and nanofluid in coiled tubes heat exchanger were numerically studied. CuO-water nanofluid containing 1 vol% copper oxide nanoparticles was used and single-phase approach was considered for nanofluid flow. The effect of different geometrical para...

The transient process accompanied by extreme acceleration in the conical sections of hydraulic systems (e.g., draft tube, diffuser) can induce large cavitation bubbles both at closed ends and bulk liquid. collapses cause severe damage to solid walls. We conduct experiments tubes with different conical-frustum shaped `tube-arrest' method observe generated these two locations. For close end we pr...

INTRODUCTION Spontaneous sedimentation is an important procedure for stool examination. A modification of this technique using conical tubes was performed and evaluated. METHODS Fifty fecal samples were processed in sedimentation glass and in polypropylene conical tubes. Another 50 samples were used for quantitative evaluation of protozoan cysts. RESULTS Although no significant differences ...

This study evaluated the quality and bacteriologic safety of platelet-rich plasma (PRP) produced by 3 simple, inexpensive tube centrifugation methods and a commercial system. Citrated equine blood collected from 26 normal horses was processed by 4 methods: blood collection tubes centrifuged at 1200 and 2000 × g, 50-mL conical tube, and a commercial system. White blood cell (WBC), red blood cell...

Tube flaring process involves a conical tool of certain length which is displaced to get an end flared tube, utilized form tight seal between pipes or tubes. refers kind forging often cold working operation. The tube forming widely used in several industries condenser pipes, car seat structures, exhaust piping, etc. Thin-walled tubes were automobiles reduce the total weight for better performan...