Polyacrylonitrile nanofibrous tubular structures were produced through typical and opposite charge electrospinning methods and the effect of the method as well as the two key electrospinning parameters, namely concentration of the electrospinning polymer solution and rotational speed of mandrel collector on properties of such tubular structures were studied. The smples were characterized by...

in this study, the characteristics of the wake around a rotating circular cylinder have been investigated experimentally. to this end, a cylinder with a circular cross-section of plexiglas with the length of 400 mm and a diameter of 20 mm have been tested in the wind tunnel. using existing methods, the characteristics of the wake and the drag coefficients of the model in different cases have be...

The growing number of civil applications in which Unmanned Aerial Vehicles (UAVs) are involved can create many concerns for airspace security and surveillance. Gathering as much information possible about a drone be crucial to apply proper countermeasures if potentially dangerous situation is detected. Of course, the presence UAV detected by radar, but it extend system capabilities obtain addit...

Abstract The advent of chirped-pulse Fourier transform microwave spectroscopy has dramatically increased the acquisition rate high-resolution data. However, this data is only useful when it can be translated into molecule-specific information, and ultimately chemical knowledge. To adapt to high regime, new analysis tools, which do not result in commensurate increases time, are needed. Several m...

distribution of water vapor in the atmosphere of the room poultry houses is usually an effective and economical solution to reduce heat stress of the chickens. experimental studies were conducted in a small saloon located in the farm machinery department of shiraz university. the rotary cup fogging system consisted of a cup which was derived by dc motor. rotational speed of the cup caused the w...

Solidification rate of the casting affects greatly on the microstructure, quality as well as the mechanical properties of the casting. In centrifugal castings solidification rate is faster compared to gravity casting but still solidification depends on various process parameters like, die wall temperature, pouring temperature of the molten metal, wall thickness of the die and also rotational sp...

In this article effects of friction stir welding (FSW) tool rotational and traverse speeds were studied on heat generation and temperature distribution in welding zone of AA1100 aluminum alloy and A441 AISI joint. Computational fluid dynamics method was used to simulate the process with commercial CFD Fluent 6.4 package. To enhance the accuracy of simulation in this Study, the welding line that...

This paper presents the design optimization and characterization of a microscale, permanent-magnet (PM) generator, capable of supplying 8 W of dc power to a resistive load at a rotational speed of 305 000 rpm. The generator is a three-phase, axial-flux, PM machine, consisting of a stator with Cu surface windings and a multi-pole SmCo PM rotor. Optimization of the machine geometries has enabled ...