cylindrical thin-walled tubes due to construction and easy installation, high energy absorption capacity are used in the automotive industry as an impact energy absorber. however, the main weakness of cylindrical tubes is in the high initial peak load. therefore, in this paper, to overcome this weakness, a buckling initiator is used at the top of the tube. this buckling initiator is a steel rod...

One-dimensional digital waveguides are widely used to model traveling pressure waves along wind instrument bores comprised of concatenated cylindrical or conical sections. Waveguide filter elements model frequencydependent losses and delay (dispersion) occurring during propagation and at any boundary or discontinuity producing reflected and transmitted waves. In this work, a technique is descri...

introduction : hospital infections are one of the important reasons of mortality and incurred expenses. therefore, we must control these infections by identifying contamination sources. the aim of this study was the determination of bacterial pollution of corrugated anesthesia sets in surgical rooms. methods: this study was an analytic-description one performed in training hospitals of yazd cit...

Conical diffusers of various configurations are used in many kinds technical equipment and manufacturing processes. Therefore, it is a relevant objective to obtain reliable experimental mathematical data on the aerodynamic characteristics diffusers. This article presents aerodynamics stationary flows vertical conical diffuser when air supplied through tubes with cross sections (circle, square, ...

Improvements in miniaturization and boosting the thermal performance of energy conservation systems call for innovative techniques to enhance heat transfer. Heat transfer enhancement methods have attracted a great deal attention industrial sector due their ability provide savings, encourage proper use sources, increase economic efficiency systems. These are categorized into active, passive, com...

The present work is concerned with a numerical study of the performance of a conical annular centrifugal contractor through the analysis of the flow properties when the apex angle is changed for different imposed axial flows. The calculations revealed the advantage of using conical annular centrifugal contractors compared to the cylindrical annular centrifuges. The study is conducted by a compa...

This 3D finite element study assessed the stress distribution in mandibular overdenture supported by the 3i Locator system attached to two cylindrical or conical implants placed at the canine region. A 100 N vertical load was applied over the right first molar of the two overdenture models. The von Mises stresses were concentrated at the cervical and middle implant thirds. Cylindrical implants ...

Few-moded or over-moded horns are now being proposed for far-IR space receiver systems, e.g. the High Frequency Instrument (HFI) on the ESA PLANCK Surveyor. In such systems individual waveguide modes can couple independently to an overmoded detector (such as a bolometer in an integrating cavity). We consider in detail the case of a cylindrically symmetric configuration consisting of a corrugate...

the researches have made different explanations about rhytons, but they mostly accepted that “rhyton is a kind of a drinking vessel often in the form of an animal, having two holes for pouring water.” rhytons were used in iran from forth millennium b.c. to the end of sasanian period. the animals that are used are of two different kinds: imaginary animals or the real animals. diversity of the sh...